SOME KEY PIONTS The introduction of new animals poses the single great risk to biosecurity on sheep farms. New (or returning) animals should be quarantined for 30 days, away from the main flock. New animals should be dewormed (with drugs from all three groups) during quarantine to prevent the introduction of resistant worms. Foot rot usually walks onto a farm; be sure to inspect hooves while animals are in quarantine. The best way to keep sheep healthy is to maintain a closed flock or by limiting introductions to new rams. Biosecurity refers to the management practices that are undertaken to prevent the introduction and spread of diseases. Healthy animals are the cornerstone of a successful sheep enterprise, regardless of the reasons for sheep ownership. These days, there is a heightened awareness of biosecurity due to the risks of bioterrorism and the fear of introducing foreign diseases such as foot-and-mouth disease into the United States. Individual states are also interested in keeping diseases from within their borders. Biosecurity is important no matter what size flock or farm you have. It only takes one sheep to introduce a new disease and one farm to start a disease epidemic. Acquisition of new animals The introduction of new animals poses the single greatest risk to biosecurity on a sheep farm. While livestock may appear outwardly healthy, they could be carrying a wide variety of diseases. Anytime a new animal is introduced to the flock, there is a potential risk of that animal introducing a new disease. It is important to note that sheep and goats share most of the same diseases. Sheep and goats also share some diseases with cattle and camelids. Before adding new sheep to your farm/flock, it is important to know the health status of the farm/flock(s) from which you are buying or receiving animals. Do not be afraid to ask questions about the farm's health program and disease status of the flock. Only buy sheep from reputable breeders. Ideally, you should purchase sheep from closed or mostly-closed flocks. A closed flock is a flock that has not introduced new animals for the past three or more years. It is best to buy sheep from as few sources as possible. It is generally not recommended that breeding stock be purchased from a sale barn (stockyard, public livestock auction). There is even a risk when you purchase sheep from a consignment sale or fair, as sale animals have contact with other livestock and you do not have a chance to inspect the farm where the sheep originate. You should not purchase animals from flocks or farms in which you observe lameness, abscesses, soremouth, ringworm, cloudy eyes, or other clinical signs of disease. While healthy-appearing animals may still be harboring these diseases, many diseases can be avoided by thoroughly observing and inspecting the animals you purchase and the farm from which they originate. Inspect for soundness Mature ewes can be a good option when starting or expanding a flock, but you need to make sure they are healthy and sound. When purchasing mature ewes, be sure to palpate their udders to make sure they don't have any lumps, scar tissue, or hard spots, which could be indicative of mastitis. If both halves of the udder are "hard," the likely cause is ovine progressive pneumonia (OPP). Examine their teeth to determine their age and soundness. Ewes with broken mouths may only have few productive years left. Palpate the testicles of rams. Do not purchase rams with reproductive abnormalities or structural defects. Make sure their mouths are sound, too. Ovine progressive pneumonia (OPP) To prevent the introduction of OPP to your flock, try to purchase animals from OPP-free flocks, as verified by test results. Unfortunately, there are not nearly enough flocks that test and cull for OPP -- despite a study showing that 26 percent of sheep in the U.S. are infected with the OPP virus. Cross transmission is possible between OPP and CAE (caprine arthritic encephalitis) so make sure if there are goats on the farm that the goat herd is CAE-free. Scrapie To prevent the introduction of scrapie to your flock, try to purchase animals from USDA certified scrapie-free flocks or enrolled flocks. The purchase of sheep with scrapie-resistant genotypes (RR or QR) will also help to prevent scrapie from occurring on your farm. Fortunately, the prevalence of scrapie in US sheep is low and the country is coming close to eradicating the disease. With this said, the last cases of scrapie will be the hardest to find. Isolate new sheep Newly-purchased sheep should be isolated for at least 2 weeks, preferably 30 days, before being co-mingled with other animals on your farm or being turned out to pasture. A period of isolation provides an opportunity to detect a disease problem before the rest of your sheep or premises are exposed. Isolation/quarantine areas should not share the same space with the rest of the flock. A distance of at least 100 feet is recommended. The farther the isolation pen is from the rest of the flock, the better it is. The isolation area should be confinement, ideally another building. If another building is not an option, you should select a corner of your barn for isolating new animals. Isolated animals should not have nose-to-nose contact with the rest of the flock. While in isolation, new animals should have their hooves trimmed and inspected for footrot and other hoof problems. It is not a bad idea to assume that any new animal has been exposed to foot rot. Making the sheep stand in a footbath of zinc sulfate is a good preventative measure to keep footrot off a farm. Koppertox or a zinc sulfate spray can be used on the hooves of individual animals. An antibiotic can be used to treat foot rot. Footrot is usually introduced (via bacteria) to a farm through the introduction of infected animals. Foot scald, on the other hand, is caused by a bacteria that is already present in sheep (and other livestock). To prevent the introduction of drug-resistant worms, new animals should be dewormed with dewormers from all three dewormer classes: albendazole + moxidectin + levamisole. A fecal egg count 10 to 14 days after treatment will indicate whether or not the treatment was effective. A negative or near zero fecal egg count is the goal. It will be helpful to learn the deworming history of the farm from which you purchase or receive new animals: which dewormers have they used and how often do they deworm. Buying animals at a sale barn Purchasing animals at sale barns (or stockyards) greatly increases the risk of a new disease entering your farm and infecting your flock. When you buy animals at a sale barn, there are no guarantees, written or otherwise, that the animals are free from contagious diseases. Since there are no health requirements to sell at a sale barn, it is possible to take animals infected with soremouth, pinkeye, caseous lymphadenitis, footrot, or other contagious diseases to a sale barn. These animals can expose healthy animals at the sale barn. In addition, most producers take their cull animals to sale barns. An animal that looks okay may actually be harboring a disease or other problem that will prevent it from being a productive animal. Buyer beware! Despite the risks, sale barns can be a viable source of slaughter and feeder lambs and even breeding stock. However, sale barn animals should only be purchased for breeding by experienced shepherds who know what they are doing. It is best to purchase ewe lambs and ram lambs for breeding since there is less chance of them introducing reproductive diseases or problems. If you purchase animals from a sale barn and bring them to your farm, be sure to keep them separate from the rest of your flock. Separate barns and pastures for sale barn animals will lessen the chances that you will introduce a new disease to your farm. If you plan to add sale barn animals to your flock, you should quarantine them for at least 60 days. The risk of showing Taking your animals to shows and other exhibitions greatly increases the risk that you will introduce a new disease to your farm. Contact with other animals at a fair can expose your animals to various infectious agents. Try to minimize the nose-to-nose contact your animals have with other animals at the fair. While at the fair, try not to share equipment, waterers, or feeders with other exhibitors. If you loan your equipment to someone, make sure it is disinfected before you use it on your animals. When you return from a show, isolate your show animals from the rest of your flock. Treat them as if you just purchased them. Shearing Some diseases can be introduced and spread by shearing. Of particular concern is caseous lymphadenitis, an infectious, contagious disease that is the third leading cause of carcass condemnation in cull ewes. To prevent infections from being introduced and/or spread, shearers should disinfect their equipment between flocks and between sheep. Shearing the youngest sheep first will also help to prevent the spread of disease. Club lamb fungus (ringworm) has become common among show lambs. Shearing equipment and frequent close shearing are the primary reasons for the disease's spread. Good hygiene, careful shearing, and less frequent grooming may help to limit the spread of the disease to other sheep and people. Do not share equipment without proper disinfecting. Limit access to your farm and flock Some diseases can be spread by contaminated footwear and vehicles. By limiting access to your farm and sheep, you can limit the risk of introducing and spreading diseases. When people are given access to your sheep flock, they should not have been on another sheep farm for several days. They should be required to wear plastic boots or thoroughly disinfect their footwear before entering your sheep-raising areas. Make sure trucks and trailers are clean. Persons who have been in foreign countries within the prior 5 days should not be allowed to visit your farm. If you travel to a country that has foot-and-mouth disease, it is best to leave your protective clothing and shoes there. Good management Rodents, cats, and other wildlife can harbor infectious agents. Some method of rodent control should be employed on the farm. Usually, this is cats. To prevent ewes from becoming infected with toxoplasmosis, one of the leading causes of abortion in sheep, young cats should be kept away from stored hay and grain. It is best to neuter and vaccinate any cats on the farm and maintain a healthy, stable, adult population of cats. Dead carcasses, and placenta and fetal tissues should be removed immediately from the sheep-raising areas to prevent the introduction and/or spread of diseases. The ewe should not be permitted to eat her placenta, as this can spread diseases, such as scrapie and abortion. Composting is often the best way to dispose of reproductive wastes. Under no circumstances should carcasses and other waste products be left for dogs or wild animals to eat. This attracts predators and scavengers and can spread diseases. Sheep measles (cysts in the meat) is perpetuated when dogs and other canines are allowed to consume sheep carcasses. Dogs which eat infected placentas can pass the infective organism in their feces, further infecting the premises and other sheep. Preventative health management A vaccination program provides inexpensive insurance against common sheep diseases. It is generally recommended that all sheep and lambs be vaccinated for clostridial diseases. CDT provides protection against the most common clostridial diseases: clostridium perfringins type C & D (overeating disease) and tetanus. Covexin®-8 confers protection for additional clostridial diseases. The use of Covexin®-8 and other vaccines depends upon the disease risk and diagnosis of particular diseases in the flock. Vaccines are available for soremouth, caseous lymphadenitis, vibrio and chlamydia abortion, epididymitis, and rabies. There is limited availability of a vaccine for foot rot. Some vaccines (e.g. soremouth, caseous lymphadenitis) should not be used unless the disease is already present on the farm because vaccination will introduce the disease to the farm. Such vaccines are advocated to reduce the incidence of disease, not prevent it in its entirely. Anthelmintic resistance Gastro-intestinal parasites (worms) are the primary health problem affecting sheep raised in warm, moist climates or during periods of warmth and moisture. A parasite control program that integrates management practices with targeted selective deworming (using the FAMACHA© system, 5-point check©, or performance indicators) should be implemented. Regular deworming of all animals in the flock or in a management group is no longer recommended due to the widespread existence of drug-resistant worms. To slow the development of resistant worms, it is now recommended that clinically parasitized animals be given combination treatments (dewormers from different chemical classes). Fecal egg count reduction tests should be conducted to determine which dewormers are effective on a farm. If natural products are used in the internal parasite control program, animals should be regularly monitored to see which ones require treatment with "chemical" dewormers. Abortion When a ewe experiences an abortion, she should be isolated from the rest of the flock. The dead fetus, placenta, and fetal tissues should be removed immediately and buried or composted. The lambing area should be disinfected. Antibiotics should be given (fed or injected) during an abortion storm to prevent further losses. Chlortetracycline is FDA-approved for this purpose. However, a written script must be obtained from a veterinarian. Including monensin (Rumensin®; Rx) or Decoquinate (Deccox®) in the feed or mineral during the last third of pregnancy may help to prevent abortions caused by toxoplasmosis. Maintain a closed flock The best way to maintain a healthy flock is to maintain a closed flock. Once the genetics of the ewe flock has been established, replacement females should be selected from within the flock and new acquisitions should be limited to rams. Unfortunately, artificial insemination (AI) is not a very viable option for most U.S. shepherds, making introduction of new rams periodically necessary. It may be possible for large flocks to select their own ram replacements, but for most shepherds, outside ram purchases are necessary to avoid unacceptable levels of inbreeding. Fortunately, rams spread fewer diseases than ewes. While rams can still introduce soremouth, footrot, pinkeye, or caseous lymphadenitis to a flock, they are not likely to introduce vibrio or chlamydia. They are not believed to transmit scrapie, though the use of RR rams will ensure the birth of lambs that are scrapie-resistant. Epididymitis (caused by Brucella ovis) is a concern in some geographic locations.

SOME KEY POINTS Coccidiosis is one of the most economically important diseases of sheep, especially in certain production environments. Transmission of coccidia is via the oral-fecal route. Coccidiosis can be sub-clinical (most common ) or clinical (requiring treatment). Coccidiosis is prevented with good management and hygiene (and coccidiostats). Clinical signs of coccidiosis include scours (diarrhea) and ill thrift. Coccidiosis is treated with prescription (Rx), extra label drugs. Coccidia can infect many animals, but especially mammals and birds. Coccidiosis is one of the most economically important diseases of sheep. It is caused by microscopic, single cell protozoan parasites of the genus Eimeria. With few exceptions, coccidia are host-specific meaning there is no cross-infection between hosts. Even sheep and goats are infected by different species of coccidia. None cause disease in people. At least 11 species (maybe more) of coccidia are known to infect sheep, but only two are known to be highly pathogenic: Eimeria crandallis and Eimeria ovinoidalis. Pathogenic species such as these affect both the small and large intestine. The other species which infect sheep are not known to cause any disease issues. At some point in their life, almost all sheep are exposed to coccidia and shed oocysts in their feces. However, most sheep, even lambs, are asymptomatic, as they usually develop immunity to coccidia at an early age. Life cycle Coccidia have a direct life cycle, meaning no other animal or organism is involved. Their life cycle is more complex than nematodes (worms). As with other parasites, there is a free-living stage (exogenous) which takes place outside the animal and a parasitic phase (endogenous) which takes place inside the animal (in the gut). Within the gut, there is both an intracellular and extracellular component. Coccidia undergo both sexual (gametogony) and asexual (schizogony) reproduction. The duration of the life cycle is 2 to 4 weeks, depending upon the species of Eimeria. The egg-like structure of coccidia is called an oocyst (not be confused with an oocyte, which is an immature female reproductive cell). Oocysts are extremely resistant to environmental stress, including ordinary disinfectants. They have a thick wall that protects them. However, they can be killed by heat (sunlight and drying) or extreme cold (freezing). This is why pasture is a less favorable environment than enclosed housing. However, oocysts can overwinter on pasture in small numbers. They can survive for months in the soil. The coccidia life cycle starts when oocysts are shed in the feces of infected animals. If conditions are conducive (warmth + humidity + oxygen), the oocysts “sporulate” (mature) and become infective. Animals ingest infective oocysts. Once in the gut, the oocysts break open, releasing high numbers of parasites, which invade the gut wall. Each parasite grows by asexual reproduction to produce a hundred or more “daughter” parasites. The daughter cells break out and invade fresh areas of the gut wall. Within 10 to 14 days, the parasites have multiplied by up to a million-fold. By this stage of infection, parts of the gut wall are packed with parasites, which develop into male and female sex cells. Oocysts are shed in the feces, starting the cycle all over again. From the sheep’s perspective, clinical symptoms do not usually appear until late in the life cycle. At each stage of the cycle, intestinal cells are invaded and destroyed, causing repeated damage to the intestine. The intestinal damage can release blood and cause inflammation of the lining of the gut. Villi (finger-like projections that increase nutrient absorption) are damaged. The animals lose blood, water, and protein and cannot absorb nutrients as efficiently. Coccidiosis can cause permanent damage to the animal's digestive tract. Some animals may never thrive, despite treatment. Some die. As with other gastro-intestinal parasites, immunity is acquired with a gradual exposure to the parasite. Sheep develop immunity to coccidia sooner than nematodes (roundworms). However, if exposure to coccidia overwhelms the animal’s immune system, clinical disease results. This is particularly true of young lambs, whose immune systems are still developing. Disease is rare in adult animals, but they serve as reservoirs of infection. Transmission Transmission is the oral-fecal route. Lambs become “infected” when they consume sporulated oocysts. Fecal contamination of hay, grain, bedding, pasture, udders, teats, water troughs, and feeders (especially creep feeders) are all sources of infection. Environmental build-up of coccidia occurs in the barn and dry lot, as well as areas on pasture. Transmission of coccidiosis to lambs favors warm and wet environmental conditions. Clinical disease often erupts during the transition from winter to spring. Outbreaks are often related to seasonal changes in rainfall. Extreme weather can trigger disease. While there is disagreement as to whether colostrum provides newborns with protective immunity to coccidiosis, very young lambs (< 3 weeks) are not usually affected. Lambs, 1 to 6 months of age, are at greatest risk for coccidiosis. Those under 3 months of age are most commonly affected, though older lambs may exhibit poor performance, due to earlier infections. Coccidiosis affects both nursing lambs and growing lambs that have been weaned. Disease outbreaks are most common in intensively-managed flocks. While coccidiosis is considered more of a risk with housed animals, intensive grazing situations can create similar environmental conditions, resulting in disease outbreaks. Overcrowding (or stocking) is one of the primary risk factors associated with outbreaks of coccidiosis. Coccidiosis is often seen with other diseases, such as pneumonia and sore mouth (orf). Diagnosis As with many diseases, there are two forms of coccidiosis: subclinical (chronic) and clinical (acute or severe). Subclinical coccidiosis often goes unnoticed, as symptoms may not be apparent. Mostly, subclinical coccidiosis reduces performance (growth and feed conversion) of lambs. It is the most common form of the disease and most costly. Clinical coccidiosis is when disease symptoms are observed. Without effective treatment of clinically-parasitized animals, serious damage or death can occur. Diagnosis of coccidiosis can be difficult, as other diseases present with similar symptoms and fecal oocyst counts are not a reliable method of diagnosis, at least not by themselves. When making a diagnosis, factors to consider are epidemiology (who, when, and where), clinical signs, fecal oocyst counts (and speciation), response to treatment, and post-mortem examination of animals. Symptoms Coccidiosis should be suspected any time there are digestive problems in young animals that are being raised under intensive conditions. The most common sign of coccidiosis is scours (diarrhea). Feces are usually brown and soft. They may be foul-smelling. Liquid (watery) feces are common with severe infections. Sometimes, feces are smeared with blood or mucous. Affected lambs exhibit symptoms consistent with ill thrift: lethargy, weakness, anorexia, dehydration, loss of weight and body condition. A hollow, hunched-up appearance is common among clinically-parasitized lambs. Lambs may strain to defecate, which could result in rectal prolapse. They may experience abdominal pain. Their abdomen may be distended (pot-bellied). Fever is not common, but parasitized lambs may have pale mucous membranes (anemia). Severe infections could result in death. Fecal oocyst counts (OPG) aid in diagnosis, but are not a definitive method of diagnosis, because there is not always a strong relationship between oocyst counts and the severity of disease. Large numbers of oocysts (e.g. 100,000 OPG) have been found in animals that are unaffected, while (clinical) disease may be present in animals with few oocysts in their feces. The other reason fecal oocyst counts are not a definitive method diagnosis is because not all coccidia are pathogenic. To be useful, fecal analysis should include speciation. However, this is seldom done, except under research conditions. Despite the general relationship between clinical coccidiosis and oocyst excretion, no threshold for treatment has been established, though a fecal oocyst count of >20,000 OPG of a pathogenic species is considered characteristic of coccidiosis in lambs. A necropsy is the most reliable method of diagnosis. The most common finding is multiple, raised white lesions on the intestinal mucosa. 1 to 6 mm in diameter. Thickening of the intestinal wall, due to edema, is not uncommon. In acute cases, the intestinal lumen may contain blood. The coccidia organisms themselves cannot be seen at necropsy, as they are microscopic. Prevention As with other diseases, prevention of coccidiosis is far more cost effective than treatment. This is because by the time clinical signs have appeared, most of the damage has already been done. Good hygiene Prevention starts with good husbandry practices, especially sanitation. Since coccidiosis is transmitted in the manure, it is important that animals be raised in hygienic conditions. Pens should be stocked according to industry recommendations. In fact, it is probably a good idea to exceed space requirements. The barn or birthing facility should be cleaned before lambing. Pens need to be kept clean and dry. In intensively-managed sheep operations, it may be necessary to bed daily. Removal of soiled bedding is ideal, but generally not practical. Moreover, excessive cleaning of cement floors may be more conducive to organism survival, as moisture is more likely to accumulate in a thin layer of manure. Frequent clean-out is generally not necessary if the bedding on the top of the manure pack is clean and dry. It is especially important to keep lambing jugs clean. Ideally, jugs should be cleaned and limed between births. Slatted floors will greatly reduce transmission of coccidia. Feeders need to be kept free from fecal matter. Designs which prevent fecal contamination should be favored. Fence line feeders are a good way to minimize fecal contamination. Hay can be fed in racks. It may be necessary to cover hay racks to keep animals out. A horizontal bar will help to keep lambs out of creep feeders. Elevated feeders are preferred to feeders at ground level. Open troughed feeders are especially problematic, as lambs like to play and sleep in them. Feed pans or troughs should be removed or turned over after feeding. No feed should be fed on the ground. Water receptacles must also be kept free from fecal contamination. Areas around water troughs need to be kept dry. Leaky waters need to be fixed. Water should not be allowed to overflow. Good nutrition Good nutrition is essential to maintaining high levels of immunity in all animals. Good nutrition starts with colostrum (the first milk). Pregnant ewes should be fed to optimize the quality and quantity of colostrum that they produce. Ewes in good body condition will produce more milk and better-quality colostrum than ewes that are thin. Mature ewes usually produce better colostrum. Land O’Lakes markets a colostrum substitute if ewe’s milk is insufficient. Lambs need to consume adequate amounts of colostrum. Even if the colostrum doesn't provide specific antibodies to coccidia, it improves the lamb's immune function. The sooner colostrum is consumed, the better. Colostrum is only produced for the first 24 hours by the ewes. The lamb’s ability to absorb antibodies diminishes with time. Absorption is most efficient in the six hours after birth. The recommended consumption of colostrum is 10 to 15 percent of body weight. Colostrum can be fed with a bottle or tube fed to at-risk lambs or those whose dams lack sufficient colostrum. Balanced rations, with the appropriate amounts of energy, protein, vitamins, and minerals, should fed to all animals at all times. There is software that can be used to balance rations. Animals in better body condition are better able to tolerate parasite and disease challenges. Body condition score can also be used to make treatment decisions. It is part of the Five Point Check©. It is important that there is always enough feeder space. In fact, it’s never a bad idea to exceed industry recommendations for feeder space. Competition for feeder space is an added stress. Young lambs should not have to compete for feeder space with older, bigger lambs. When there is not enough feeder space, it is always the smaller, weaker lambs that will be pushed out. Because coccidiosis is frequently observed in newly-weaned lambs, it is essential that weaning be carried out as stress-free as possible. Weaned lambs should always be kept in familiar surroundings, with their same pen-mates. It is the ewes that should be moved to another location for drying off. While fence line weaning may be advantageous to other species, it does not appear to reduce the stress level in lambs. It is important that lambs be consuming the same diet after weaning, as they were consuming before weaning. Lambs of different age and management groups should not be mixed, especially at the time of weaning. Tight birthing periods make it easier to batch manage lambs. To avoid additional stress, any management practice should be performed prior to weaning. In extensive production systems, pasture rotation will help to minimize exposure to infective oocysts. Lambing should take place on clean, well-drained pastures. Avoid grazing in low-lying areas and near streams and ponds. Since animals tend to defecate near water troughs, it may help to move water troughs and feeders around. Low stocking densities will go a long way towards preventing outbreaks of coccidiosis on pasture. Because coccidiosis is often seen with other disease conditions, it is important to control other diseases in the flock. Anything that lowers the immunity in the lamb will make it more susceptible to coccidia infection. It can be too difficult for lambs to fight more than one disease at a time. There are vaccines for pneumonia and sore mouth. Ventilation is key to controlling respiratory problems in housed animals. Be aware of the build-up of ammonia in the barn. Ewes and lambs should be vaccinated for clostridial diseases. Foot rot should be controlled or eliminated (ideally) from the farm. There are numerous strategies for controlling other gastro-intestinal parasites. Outbreaks of coccidiosis are often associated with shipping (transportation) stress. Ideally, newly-weaned lambs should not be shipped. When transportation is required, industry recommendations should be followed. Lambs should be loaded using low stress handling techniques. They should not be overcrowded in trucks and trailers. Lambs should not be worked or transported in the heat of the day. You should not loan your ram(s) to another farm, unless the health status of the flock is equivalent to yours (or better). You should not allow other producers to bring ewes (or does) to your farm for breeding, unless the health status of their flock is equivalent. There are other ways to help 4-Hers and new shepherds besides making your farm and animals available to them. Producers are encouraged to develop a written biosecurity plan and to follow it to prevent the introduction of diseases and other problems. Genetic control There is some evidence that some breeds and individuals are more resistant to coccidia infections and that heritabilities are similar to nematode (worm) resistance. However, data is lacking, as far less research emphasis has been placed on protozoan parasites, as compared to nematodes. So far, no long-term selection studies have been conducted. Repeatability estimates for oocyst counts suggest that selection for resistance to coccidia should be theoretically possible. At the same time, it would be difficult to select simultaneously for resistance to both worms and coccidia, unless a favorable genetic correlation was determined, or a selection index developed. In fact, it has been hypothesized that animals that are more resistant to extracellular parasites (worms) may be more susceptible to intracellular parasites (coccidia). Using coccidiostats While there is no vaccine for coccidiosis (for sheep), coccidiostats can be added to feed, mineral, water, and milk replacer to aid in the prevention of coccidiosis. There are two coccidiostats approved for use in sheep. Lasalocid (Bovatec®) is an ionophore antibiotic. It can be fed to sheep maintained in confinement. Decoquinate (Deccox®) is a non-antibiotic coccidiostat. It can be fed to lambs. A form of Deccox® is added to some milk replacers (e.g. Pipestone). Monensin (Rumensin®), another ionophore, is not FDA-approved for sheep, but has been fed to sheep, under the supervision of a veterinarian. Monensin is highly toxic to horses. Mixing errors have caused toxicity in lambs. Bovatec® has a lower risk of toxicity than Rumensin®. Deccox® is the safest to use. Coccidiostats have an effect on different stages of the coccidia life cycle. The ionophores kill coccidia, whereas Deccox® prevents its growth. Bovatec® kills the “free living” stages of coccidia, as they move from cell to cell in the intestine, while Rumensin® works on three different stages of development. Deccox® provides the widest range of activity of all the coccidiostats. When used properly, all of the coccidiostats can reduce oocyst output significantly, while allowing lambs to develop immunity to coccidia. The effectiveness of coccidiostats depends upon two key factors: timing and dosage. Coccidiostats must be fed early in the coccidia life cycle before the onset of clinical signs (usually 3-4 weeks ahead of time). Coccidiostats must be consumed at sufficient (labeled) levels. Adequate consumption is challenging since coccidiostats are often contained in free choice feeds or mineral. Consumption of feed by lambs can be variable. Underdosing is a big problem in nursing lambs. Forage consumption further reduces intake of the drug. As lambs get older, it may necessary to change the feed mixture to make sure they are consuming the proper amount of the coccidiostat. Coccidiostats should be fed strategically. They should not be fed year-round, as year-round use may increase the probability of resistance. Anecdotal reports suggest that some farms may have resistance to Bovatec®. It is common to feed a coccidiostat to ewes during late gestation, though there is disagreement as to whether this is a necessary management practice. The rationale is that feeding a coccidiostat will reduce contamination of the lambing area, thereby reducing exposure of the lambs. There is evidence that there is an increase in oocyst excretion (similar to worms, though not as high) by the periparturient ewe. Feeding ionophores in late pregnancy may have an added benefit of reducing exposure to toxoplasma gondii, cat coccidia (the only coccidia species that is not species-specific). Toxoplasmosis is a common cause of abortion in ewes. Other potential benefits of coccidiostats may include increased feed efficiency, enhanced growth rate, and reduced incidence of free-gas bloat. Treatment Once a diagnosis has been made, it is important to initiate treatment immediately to prevent permanent damage and death losses. All animals sharing the same space should be treated. Anthelmintics (dewormers) do not have an effect on coccidia. The drugs that are used to prevent coccidiosis are not same ones that are used to treat clinical disease. Currently, there are no drugs FDA-approved to treat coccidiosis in sheep. Extra label drug use is required. Extra label drug use is when a drug is used in any manner that is not listed on the product insert or label. For example, Corid® is not labeled for sheep. A different dose or route of administration also constitutes extra label drug use, as is using a drug to treat a disease that is not listed on the label. Only licensed veterinarians have the right to use or prescribe drugs extra label. For a producer to use a drug extra label, a valid veterinarian-client-patient relationship (VCPR) must exist. This usually means that the veterinarian must have familiarity with the farm and the animals treated. It is important that all producers comply with extra label drug requirements. Amprolium (Corid®) is used to prevent and treat coccidiosis in sheep. It is added to the drinking water (as a preventative) or administered as a drench (as a treatment). The dilution is different, depending upon the intended use: prevention vs. treatment. Corid® is considered more effective as a treatment, as it acts late in the coccidia life cycle, after coccidia have already done some damage. There is anecdotal evidence that there is resistance to Corid® on some farms, especially goat farms. While Corid® can be purchased over-the-counter at a feed or farm supply store, it is not labeled for sheep. Therefore, its use requires veterinary supervision. Corid® is usually given for 3 to 5 days. It has a unique mode of action. It mimics thiamine (vitamin B1). For this reason, care should be taken when using it, as there is some risk of polioencephalomalacia (thiamine deficiency) with high doses and prolonged use. Sulfonamides such as sulfamethazine (Sulmet®) or sulfadimethoxine (Di-Methox®) are the other drugs commonly used to treat coccidiosis in sheep. As with other water-soluble antibiotics, sulfa drugs must be obtained from a veterinarian and used under veterinary supervision. Like Corid®, sulfa drugs are added to the drinking water or administered as a drench. Drenching is always preferable, as it ensures that an animal, especially a clinically-parasitized one, gets the proper dose of the drug. Sick and nursing animals are not likely to drink enough water for treatment. Three to five days is the usual treatment duration. There is some toxicity risk with sulfa drugs if they are overdosed or used for prolonged periods. Animals should be weighed to make sure a safe and effective dose is administered. Lambs that are treated may require additional supportive care, such as re-hydration. Probiotics may help with appetite. After treatment they should be moved to a clean pen, either a pen with clean bedding or an uncontaminated pasture. Good nutrition should be provided. While producers are fortunate to have medical choices for treatment and control of coccidiosis, the emphasis should be on management options, aimed at reducing exposure to the infective organism and improving immunity of the animal. Other drugs Experimentally, ponazuril has been used to treat coccidiosis in kid goats. A single dose (10 mg/kg) was found to as effective at reducing oocyst counts as a five-day treatment of Corid® (50 mg/kg). Ponazuril is a metabolite of toltrazuril. In the US, it is available as Marquis®, a paste used to treat protozoal myeloencephalitis in horses. Outside the US, there are other treatment options. Totrazuril (BayCox®) and diclazuril (Vecoxan®) are licensed in Europe and other countries for the control of coccidia in sheep (and calves). Toltrazuril (20 mg/kg) is usually effective as a single treatment, whereas diclazuril (1 mg/kg) may require two treatments. Research has shown toltrazuril to be a more effective treatment option as compared to diclazuril, as it has a longer duration of action. Farm history dictates when to give both drugs, as they should be given prior to the onset of symptoms. Toltrazuril has a very long withdrawal period (48 days for lambs), whereas diclazuril has no meat withdrawal. Toltrazuril can be obtained in the US, but it is illegal to use. Natural control Researchers continuously search for more "natural" methods to control internal parasites, including coccidiosis. One of the most promising is sericea lespedeza. Sericea lespedeza (Lespedeza cuneata; CL) is a perennial, warm season legume, often called “poor man’s alfalfa," because it can be grown under sub-optimal soil conditions. It can be grazed or fed as hay, silage, or (leaf meal) pellets. Considerable research has demonstrated the effectiveness of SL in the control of Haemonchus contortus (barber pole worm). More recently, researchers have discovered that SL has a similar effect on coccidia. Lambs consuming SL diets have lower oocyst counts and less clinical signs (of coccidiosis) than those consuming control diets. It is the condensed tannins in SL that give it its anti-parasitic properties. To aid in the control of coccidiosis, researchers recommend that lambs be fed a SL diet 1 to 2 weeks prior to weaning and for 3 to 4 weeks after weaning. Continuous feeding of SL is not recommended, due to potential anti-nutrition factors. Unfortunately, SL pellets are not widely available, and when they are available, they can be pricy. The only company (simsbrothers.com) that produces SL pellets is located in Alabama. Oregano and other essential oils have shown some promise in the control of coccidiosis, especially in poultry. More research is needed before they can be recommended as control options for sheep. Because the poultry industry is so much larger and coccidiosis is a wider spread problem, this is likely where “natural” prevention/treatment options will emerge. There are commercial vaccines for coccidia control in poultry. The nematode-trapping fungus Duddingtonia flagrans sold as BioWorma® unfortunately has no effect on the life cycle of coccidia.

SOME KEY POINTSThere are many diseases for which sheep/lambs can be vaccinated.The only universally recommended vaccination is for clostridial diseases. Ewes should be vaccinated for clostridial diseases in late pregnancy to maximize immunity their lambs receive via consumption of their colostrum.Lambs should be vaccinated twice for clostridial disease, approximately 4 weeks part.Vaccinations are an important part of a flock health management program. They provide inexpensive "insurance" against diseases that commonly affect sheep and lambs. According to the National Health Monitoring Service (NAHMS, 2011), 81.6 percent of US sheep operations vaccinated at least one sheep or lamb in 2010. The two vaccines used by the highest percentage of operations were enterotoxemia and tetanus (both clostridial diseases).Table: Percent US farms that vaccinated their sheep in 2010VaccinePercent US sheep farms7 or 8 way clostridial29.5Clostridium perfringins type C & D71.4 Tetanus64.5Campylobacter (vibrio)15.2 Sore mouth 11.0Chlamydia (EAE)8.1Leptospirosis4.2Foot rot 3.5Caseous lymphadenitis3.4IBR-PI-3 (respiratory)2.7Pasteurella (pneumonia)2.1Rabies1.9 E. coli0.9Source: National Animal Health Monitoring Service, 2011 A new NAHMS study was conducted in 2024. Results are pending.Clostridial DiseasesThe only universally-recommended vaccine for sheep and lambs is for clostridial diseases. There are 3, 7, 8, and 9-way vaccines. CDT provides three-way protection against enterotoxemia caused by Clostridium perfringens types C and D and tetanus (lockjaw) caused by Clostridium tetani. It is the vaccine most commonly administered to sheep and lambs. The 7, 8, and 9-way clostridial vaccines provide protection against additional clostridial diseases, including blackleg and malignant edema. The extra protection provided by the 7, 8, or 9-way vaccines may or may not be necessary, depending upon the farm/ranch. It is best to consult with a veterinarian. Type CEnterotoxemia type C, also called hemorrhagic enteritis or "bloody scours," affects lambs mostly during their first few weeks of life, causing a bloody infection in the small intestine. Type C enterotoxemia is often related to indigestion and is predisposed by a change in feed, such as beginning creep feeding or a sudden increase in the milk supply, perhaps caused by the loss of a littermate. The only way to protect lambs from type C enterotoxemia is to vaccinate their dams during late pregnancy.Type DEnterotoxemia type D is "classic" overeating disease. It is also called "pulpy kidney disease." Type D enterotoxemia usually affects lambs that are over one month of age. Usually it is the largest, fastest growing lamb(s) in the flock that are stricken. Type D overeating disease is usually precipitated by a sudden change in feed that causes the bacteria, already present in the lamb's gut, to proliferate, resulting in a toxic, usually fatal reaction. Type D is most commonly observed in lambs that are consuming high concentrate diets, but can also occur in lambs nursing heavy milking dams.Passive immunityVaccination is not usually very successful in young lambs, under 6 weeks of age. For this reason, vaccination strategies usually recommend vaccinating the pregnant ewe to confer passive immunity to lambs via colostrum (the dam's first milk). Ewes should be vaccinated with the CDT toxoid approximately 4 weeks prior to lambing. Ewes lambing for the first time will need to be vaccinated twice in late pregnancy, approximately four weeks apart. Maternal antibodies will protect lambs for six to eight weeks so long as lambs consumed sufficient amounts of colostrum. It is generally recommended that lambs consume 10 percent of their body weight in colostrum. Ewes differ in the quantity and quality of colostrum they produce.LambsLambs should receive their first clostridial vaccination when they are approximately 6 to 8 weeks of age, followed by a booster 4 weeks later. If pastured animals are later brought into confinement or dry lot for concentrate feeding, a third vaccination should be given. Some experts recommended giving artificially-reared lambs more frequent vaccinations, as they are especially at-risk.Lambs whose dams were not vaccinated for C and D can be vaccinated with some success at two to three days of age and again in two weeks. However, later vaccinations will likely be more effective, as colostral antibodies usually interfere with vaccinations at very young ages. The lamb's immature immune system may also not be able to respond to vaccination at such a young age.A better alternative may be to vaccinate offspring from non-vaccinated dams when they are approximately 4 weeks of age, followed by a booster 4 weeks later. When lambs are vaccinated at a young age, it is recommended that a third booster be given. Anti-toxins can provide immediate short-term immunity if dams were not vaccinated or in the event of disease outbreak or vaccine failure.Feeder lambsPurchased feeder lambs should be vaccinated for type D enterotoxemia at the time of purchase and 2 to 4 weeks later. Feeder lambs purchased as 4-H or FFA projects should receive two type D vaccinations, if they were not vaccinated at the farm where they were purchased.Tetanus Tetanus, also known as lockjaw, is easily prevented with vaccination. Lambs whose dams were not vaccinated can be given the tetanus anti-toxin at the time of docking and castrating. An antitoxin provides immediate short-term immunity. If a tetanus toxoid product is administered at the time of docking or castrating, it will not provide adequate immunity, as toxoids take 10 days to 2 weeks to provide immunity and require a booster for a complete immune response.Rams and mature wethers should be boostered annually with clostridial vaccines. As with ewes, they require two vaccinations the first time they are vaccinated.Other diseasesIn addition to clostridial diseases, there are various other diseases for which sheep can be vaccinated. The decision to administer additional vaccines should be based on the health of the flock, the risk of a disease outbreak, and the prevalence of diseases in the geographic area where the flock is located. In the US (for sheep), there are approved vaccines for sore mouth, foot rot, caseous lymphadenitis, abortion, e. coli scours, pneumonia, epididymitis, and rabies. There is limited availability of the foot rot vaccine. Vaccines that are not approved for sheep are also sometimes used. They should only be used on the advice of a veterinarian as part of a valid veterinarian-client-patient relationship.SoremouthSoremouth (contagious ecthyma, orf) is the most common skin disease affecting sheep (and goats). It is caused by a virus in the pox family. There is a vaccine for it. The vaccine contains the live virus. It causes sore mouth infection (lesions) at a location (on the animal) and time of the producer’s choosing. Ewes should be vaccinated well in advance of lambing. Show animals should be vaccinated well in advance of the first show.To use the vaccine, a woolless area on the animal is scarified, and the re-hydrated vaccine is applied to the spot with a brush or similar applicator. Ewes can be vaccinated inside the ear or under the tail. Lambs can be vaccinated inside the thigh. Because the sore mouth vaccine is a live vaccine and soremouth is highly contagious to humans, care must be taken when applying the vaccine. Gloves should be worn when handling the vaccine or animals with soremouth.Flocks which are free from soremouth should generally not be vaccinated because the soremouth vaccine will introduce the virus to the flock/premises. Once soremouth vaccination is begun, it should be continued annually.FootrotFootrot is one of the most common and economically costly diseases in the sheep industry. It causes considerable economic loss due to the costs associated with treating it and the premature culling of infected or carrier animals. There are two vaccines for footrot and foot scald in sheep: Footvax® 10 Strain and Volar™ Footrot Bacterin. They may not be available for purchase in the US.Neither vaccine prevents footrot from occurring, but when used in conjunction with other management practices such as selection/culling, regular foot trimming, foot soaking/bathing, etc., vaccinations can help reduce infection levels. Footrot vaccines should be administered every 3 to 6 months, prior to anticipated outbreaks of hoof problems (i.e. prior to the wet/rainy season).Abscesses (at the injection site) are not uncommon with the foot rot vaccines. The limitation of foot rot vaccines is that they might not include the strain of foot rot that is present in a particular flock.Caseous lymphadenitis (CL)There is a vaccine for caseous lymphadenitis in sheep. CL affects primarily the lymphatic system and results in the formation of abscesses in the lymph nodes. It is highly contagious. When it affects the internal organs, it evolves into a chronic wasting disease.The cost of CL to the sheep industry is probably underestimated. The CL vaccine is convenient to use because it can be combined with CDT. Vaccination will reduce the number of abscesses in the flock, but it will not prevent the disease from occurring. Flocks which do not have CL should not vaccinate for it. Nor should flocks trying to eradicate the diseases. Sheep which have been vaccinated will test positive for CL.AbortionAbortion is when a female loses her offspring during pregnancy or gives birth to stillborn, weak, or deformed lambs. There are vaccines (individual and combination) for several of the infectious causes of abortion in sheep: enzootic (EAE/Chlamydia sp.) and vibriosis (Campylobacter fetus). There are leptospirosis vaccines for cattle.Abortion vaccines should be administered prior to breeding. Ewes being vaccinated for the first time should receive a second vaccination (booster) in mid-pregnancy. Producers with problem flocks may consider giving a booster as well. Risk factors for abortion include an open flock and/or a history of abortions in the flock.Unfortunately, there is no vaccine (available in the U.S.) for toxoplasmosis, another common cause of abortion in sheep. Since the disease-causing organism is carried by domestic cats, the best protection is to control the farm's cat population by spaying/neutering and keeping cats from contaminating feed sources.EpididymitisEpididymitis is a major cause of reduced fertility in rams from western range states. There are vaccines for epididymitis (Brucella ovis), but none are deemed fully effective. In addition, vaccination interferes with the ability to eliminate infected rams from the flock, as vaccinated rams will test positive for B. ovis. Eradication is a better course than vaccination.E.Coli ScoursScours in baby lambs can be caused by E. coli. There is a vaccine that can be administered to ewes at the same time as CDT to pass immunity to lambs through the colostrum. An alternative to vaccination is to give newborn lambs oral E. coli antibody at birth.PneumoniaThere is a vaccine for pneumonia caused by Mannheimia haemolytica and Pasteurella multicida. It requires two injections. Some producers have used a vaccine called Nasalgen® in newborn lambs. It protects against the parainfluenza virus (PI-3), which may play a role in lamb pneumonia. It is given in the form of a nasal spray. Nasalgen® is not labeled for lambs, so veterinary approval is required.RabiesThough the risk to sheep is usually minimal, rabies vaccination may be advised if the flock is located in a rabies-infected area, the animals are especially valuable, and livestock have access to wooded areas or areas frequented by raccoons, skunks, foxes, or other known carriers of rabies. Some states and fairs may require rabies vaccination. Sheep used to graze public areas may be required to be vaccinated.For most situations, the cost of rabies vaccination relative to the value of the animals should be considered. The large animal rabies vaccine is approved for use in sheep. Some states require a veterinarian to administer rabies vaccinations. All dogs and cats on the farm should be vaccinated against rabies. A strong majority of states require it.Barber pole wormThere is a vaccine for barber pole worm (Haemonchus contortus) called Barbervax®. It controls barber pole worm infection mainly by reducing egg counts and preventing reinfection. It takes three injections before immunity is established in animals not previously vaccinated. However, Barbervax® is currently not available in the US. It is not known if it will ever be sold in the US.Mastitis There is a vaccine (VIMCO) for mastitis in sheep/goats. It targets Staphylococcus aureus and CNS (Coagulase Negative Staphylococci), the bacteria most commonly associated with mastitis. It became available to US for meat and dairy goat producers in 2021, but has since been withdrawn from the US market.Autogenous vaccinesWhen no commercial vaccine is available, autogenous or custom vaccines can be made. They are usually made from bacteria or viruses that have been isolated on a farm in conjunction with a disease. Autogenous vaccines are usually not as effective as commercial vaccines.Giving VaccinesMost vaccines are given subcutaneously (sub-Q), i.e. under the skin. Some vaccines are given intramuscularly (IM). Occasionally, some are given topically (e.g. soremouth) or intranasally (e.g. Nasalgen®). For subcutaneous vaccines, a 1/2 or 3/4 inch, 18- or 20-gauge needle should be used for injections. Subcutaneous vaccinations can be given over the ribs, behind the armpit (axilla), or high up on the neck. The needle used to withdraw vaccine from the bottle should not be the same needle used to inject the animal.In order for vaccination programs to be successful, label directions need to carefully followed. Vaccines should be stored, handled, and administered properly. Only healthy sheep and lambs should be vaccinated. Wet sheep should should not be vaccinated. It is also important to note that vaccines have limitations and that the immunity imparted by vaccines can sometimes by inadequate or overwhelmed by significant disease challenge.Not vaccinatingMany sheep producers will tell you that they never vaccinate their animals and do not suffer consequences as a result of their decisions (which is probably untrue). Other producers vaccinate for diseases which are not a high risk. Vaccination is a form of risk management. Each producer must weights the pros and cons of vaccinating for a specific disease. If the cost of vaccination exceeds the expected losses, then vaccination is probably not cost-effective. Conversely, if expected losses exceed the cost of vaccination, then vaccination is a good risk management tool.At the same time, it is not advisable to wait until you have a disease outbreak before instituting a vaccination program. The risk of a disease outbreak should be the criteria that is used to determine the need for vaccination. A producer's tolerance for risk will also come into play. Vaccines are allowed and recommended in organic and "humane" production systems.

SOME KEY POINTS Internal parasites (gastro-intestinal nematodes) are the primary disease affecting sheep and lambs Heavy stocking rates and insufficient pasture rest periods are the main reasons for clinical parasitism in sheep and lambs. The worms have developed varying degrees of resistance to all dewormers and dewormer classes. It is no longer recommended that sheep/lambs be dewormed on a regular basis or that all animals in a management group be dewormed. Only sheep/goats that require deworming be treated with an anthelmintic. Combination treatments (giving drugs from different classes sequentially) is recommended for clinically parasitized sheep/lambs. A more integrated approach to parasite control is necessary. It should combine management and genetic selection with judicious use of anthelmintic drugs. In most sheep production areas, internal parasites or gastro-intestinal nematodes ( worms) are usually the primary disease affecting sheep and lambs. Sheep are more susceptible to internal parasites than most other types of farm livestock for several reasons. Their small fecal pellets disintegrate very easily thus releasing the worm larvae onto pastures. They graze close to the soil surface and to their feces. They acquire immunity more slowly. It takes 10 to 12 months for many lambs to develop immunity to parasites. Sheep also suffer a temporary loss of immunity around the time of lambing, called the periparturient egg rise. Heavy stocking rates and insufficient pasture rest periods contribute to the incidence of parasitic disease in sheep and lambs. Internal parasites tend to be much less of a problem under range-type conditions where sheep do not graze the same pasture twice in the same grazing season. They are also less of a problem in dry climates (or during dry periods) because parasites require moisture for their development. In the past, sheep producers relied heavily on anti-parasitic drugs called "anthelmintics" (dewormers) to control internal parasites in their flocks. But the long-time use and in some cases misuse of these drugs has resulted in parasites that have become increasingly resistant to anthelmintics. Drug resistance has been documented in all three drug families and is most commonly reported with the benzimidazoles and avermectins. Some farms are experiencing complete anthelmintic failure. In the U.S., few anthelmintics are FDA-approved for use in sheep and lambs, and no new drugs are likely to be approved. No combination products are available. As a result, producers must develop more integrated programs for controlling parasites, which do not rely exclusively on drug therapy. They must also learn to use the existing drugs more judiciously. The Parasites Gastro-Intestinal Worms (roundworms, nematodes, stomach worms) In warm, moist climates, the parasite that causes the most problems is usually Haemonchus Contortus, better known as the "barber pole" or wire worm. The barber pole worm is a blood-sucking parasite that pierces the lining of the abomasum (the sheep's fourth or "true" stomach), causing blood plasma and protein loss to the sheep. Females are identified as barber pole worms because their white ovaries are wound around their red blood-filled intestine. Male worms are red. The barber pole worm is the largest and most deadly stomach worm. The worms are visible during necropsy. The symptom most commonly associated with barber pole worm infection is anemia, characterized by pale mucous membranes, especially in the lower eye lid; and "bottle jaw," an accumulation (or swelling) of fluid under the jaw. Infections with barber pole worm rarely result in diarrhea (scours). Other worm species are more likely to cause diarrhea. The barber pole worm can be difficult to control because it has a short, direct life cycle and is a prolific egg layer. A female barber pole worm can produce 5,000 to 10,000 eggs per day. The barber pole worm is also capable of going into a "hypobiotic" or arrested state when environmental conditions are not conducive to its development and resuming its life cycle once environmental conditions improve. Some worm larvae are able to survive on pastures over the winter, depending upon climate. Worms usually of secondary importance include Trichostrongylus spp. and Teladorsagia (Ostertagia). Their importance is usually as an additive effect in mixed infections with Haemonchus. However, in warmer sub-tropical areas, Trichostrongylus spp. are important pathogens in grazing ruminants. Teladorsagia appears to be much less important in the United States than in cooler parts of the world such as Northern Europe and the British Isles. In the southern United States, Ostertagia circumcincta is of no real significance in small ruminants because the hot and often dry summers are hostile to the survival of its pre-parasitic stages In the western U.S. particularly the cooler, wetter, coastal areas of Washington, Oregon and Northern California, Teladorsagia is the dominant nematode of sheep (and goats). Nematodirus is not usually a significant problem in small ruminants in North America. However, Nematodirus battus does cause significant disease in lambs in Britain because of its unusual hatching requirements. Cooperia infections are usually secondary contributors to parasitic disease. Tapeworms (Moniezia expansa) Because tapeworm segments can be seen in sheep feces, they often cause alarm to producers. While experts disagree about the importance of effects of tapeworms, there is little evidence to suggest that treatment is beneficial to the host. Although dramatically large numbers of tapeworms may occupy the small intestine, damage to sheep is generally much less than that done by the gastrointestinal Haemonchus. In extreme cases, tapeworms may cause intestinal blockages. They may affect gut motility, which could predispose lambs to enterotoxemia. There is some evidence that lamb growth rates may be affected when large numbers of tapeworms are present. Tapeworms have an indirect life cycle. They require pasture mites to complete their life cycle. Only certain anthelmintics (benzimidazoles, praziquantel) are effective against tapeworms. Lungworms (Dictyocaulus filaria, Muellerius capillaris) Wet, low-lying pastures and cool, damp weather favor the development of lungworm disease in sheep. Lungworm eggs are passed in the feces. After the eggs hatch and are ingested by the sheep, they travel through the sheep's tissues to the lungs (trachea and bronchi). Only in severe infestations do lungworms produce clinical disease, causing fever, coughing, nasal discharge, rapid breathing, and poor performance. Secondary infection by bacteria may cause death. Liver Flukes (Fasciola hepatica) Liver flukes can cause death in sheep and lambs or liver damage in sub-acute cases. In the U.S., they are primarily a concern in California, the Gulf States and Pacific Northwest. Liver flukes require snails as an intermediate host. Two drugs are available in the United States for the treatment of liver flukes: Clorsulon and Albendazole. Meningeal Worm (Paralaphostrongylus tenius) The meningeal (deer or brain) worm is an internal parasite of white tailed deer. The life cycle of the meningeal worm requires terrestrial snails or slugs as intermediate hosts. Sheep are unnatural, dead-end hosts for the parasite. When sheep ingest snails containing infective larvae, the parasite moves into the brain and/or spinal cord causing often fatal neurological disease. The neurological signs observed in infected sheep depend upon the number of larvae present in the nervous tissue and the portion of the brain or spinal cord that has been affected. A mild infection may produce a slight limp or weakness in one or more legs, while a more severe infection may cause an animal to be partially or completely paralyzed. Meningeal worm infection cannot easily be diagnosed in the live animal. Treatment usually involves high, repetitive doses of anthelmintics, along with steroids and other supportive therapies. Research by Cornell University has demonstrated good efficacy with high doses of fenbendazole, along with anti-inflammatory drugs. Preventative measures include fencing off areas which receive high deer utilization and removing sheep from pastures before weather turns cool and wet. Fencing sheep away from likely snail and slug habitats (e.g. ponds, swamps, wetlands, low lying and poorly drained fields, and woodlands) may also help to prevent the problem. In high risk areas, monthly deworming (with ivermectin) has been advocated. Coccidia (Eimeria spp.) is discussed in another chapter. Integrated Parasite Management (IPM) Good Management Internal parasite control starts with good management and common sense. Sheep should not be fed on the ground (unless the ground is frozen). Feeders which cannot easily be contaminated with feces should be favored for grain, hay, and minerals. Water should be kept clean and free from fecal matter. Pastures and pens should not be overstocked. When new sheep are acquired, they should be isolated from the rest of the flock for at least 30 days and aggressively dewormed to prevent the introduction of drug-resistant worms. Use of Clean or Safe Pastures Clean or safe pastures are pastures which are not contaminated with worm larvae that affect sheep. Examples of clean pastures include pastures that have not been grazed by sheep (or goats) for the past 6 to 12 months; pastures which have been grazed by horses or cattle; pasture fields in which a hay or silage crop has been removed; pasture fields which have been rotated with field crops; and pastures that have been recently established or renovated by tillage. Pasture Rest and Rotation It is a common misconception that rotational grazing controls internal parasites in sheep. Intensive rotational grazing may actually contribute to parasitic problems. This is because rotating large groups of ewes and lambs through small paddocks concentrates livestock and infective parasite larvae onto the same small area. Researchers in the Netherlands found that it takes three months of rest for an infected pasture to return to a low level of infectivity. Researchers at Langston University (Oklahoma) determined that a 65-day rest period was sufficient (for goats). Rotational grazing is an effective management tool for managing parasites, but only if pasture rest periods are long enough (i.e. 60 days or more). On the other hand, better nutrition provided by rotational grazing may offset the effects of higher parasite loads on the pasture. Grazing Strategies Approximately 80 percent of the worm larvae can be found in the first two inches of grass. Therefore, sheep grazing taller forages should have fewer parasite problems. Sheep should not be allowed to graze forages shorter than 3 inches in height. Sheep that browse also have fewer parasite problems. Another grazing strategy is to wait until the dew has lifted from the grass or grass has dried after a rain. Dry conditions force parasites to stay at the base of the plants where they are less likely to be consumed by the livestock. Multi-species Grazing Sheep (and goats) are generally not affected by the same internal parasites as cattle and horses. Consequently, pastures grazed by cattle and horses are safe(r) for sheep (and goats) and vice versa. Sheep can be co-grazed with cattle and/or horses. A leader-follower system can be utilized or pastures can be alternated between sheep and cattle and/or horses. There are numerous other benefits to multi-species grazing. Each species has different grazing behavior that complements one another. For example, sheep prefer to eat weeds and short, tender grasses and clover, while cattle prefer to eat taller grasses. Cattle may offer some protection from predators. Alternative Forages Some pasture plants have deworming properties, such as those containing condensed tannins. Research has shown that sheep grazing tannin-rich forages have lower fecal egg counts than animals grazing traditional grass pastures. The tannins may also decrease the hatch rate of worm eggs and larval development in feces. Forage species which contain high levels of condensed tannins include sericea lespedeza, birdsfoot trefoil, and chicory. Sericea lespedeza is a warm, season legume. Birdsfoot trefoil is a long-lived perennial legume. Chicory is a low-growing, leafy perennial. Generally speaking, trees and shrubs contain higher levels of tannins than pasture grasses, and tropical legumes contain more condensed tannins than temperate legumes. Nematode-trapping fungus BioWorma® is the tradename for a product which contains spores of a fungus called Duddingtonia flagrans. When fed to grazing animals, the fungus spores trap and kill worm larvae in the manure, thereby preventing contamination of pastures. The fungus does not have any effect in the animal. Parasitized animals still require deworming. It works on the free-living stage of roundworms. It needs to be fed daily to have any effect. BioWorma® is being marketed by an Australian company. It was approved for sale in the US in 2018 and became available for purchase in 2019. There are two products. BioWorma® contains 34% fungal spores and can be purchased by veterinarians and feed mills. Livamo® with BioWorma® contains 2.4% fungal spores and is available for purchase by producers. Premier 1 Supplies, of Iowa, was the first US distributor of Livamol® with BioWorma®. It began selling BioWorma® by itself in 2020. Healthy Soil Earthworms have been shown to ingest worm eggs and larvae, either killing them or carrying them below the soil surface. Certain types of fungi will trap and kill parasitic larvae. Dung beetles ingest and disperse manure, thus keeping eggs and larvae from developing. Anything that is done to maintain soil health and promote these types of organisms will aid in parasite control. Scientists are examining the possibility of feeding nematophagous fungi to livestock to kill larvae in manure piles. Nutritional Management Supplemental feeding can aid in the control of parasites. Sheep and lambs on a higher plane of nutrition mount a better immune response to internal parasites than animals whose nutritional status is compromised. Animals on low protein diets are more susceptible to infection because they produce less IgA (immunoglobulin). Higher levels of protein have been shown to improve the pregnant ewe's immune response to parasites after lambing. Lambs receiving protein supplementation usually have reduced fecal egg counts. Zero Grazing Keeping sheep and/or lambs in confinement or dry lot (i.e. "zero grazing") is a proven means of reducing parasitism and preventing reinfection. Under a zero grazing situation, sheep and/or lambs do not have access to vegetation for grazing. They are housed in a bedded barn, dirt lot, or facility with slatted floors. Feed should be fed off the ground in feeders. Watering containers should be kept free from fecal matter. Slatted floors offer the best protection against internal parasites because sheep generally do not come into contact with their feces. Genetics Genetics is probably the best long term strategy for controlling internal parasites in sheep. Some sheep breeds are naturally more resistant and resilient to internal parasites. They include the "native" breeds of the Southeast (Florida, Louisiana, and Gulf Coast Native and the Florida Cracker) and hair sheep breeds with tropical origins: St. Croix, Barbados Blackbelly (and its derivatives), and hair sheep composites, such as the Katahdin. Grazing resistant breeds of sheep with susceptible breeds, may act to “sweep” pastures and reduce contamination to susceptible animals. Regardless of the breed raised, producers can breed sheep which are more resistant to parasites by culling ewes that are persistently affected by parasites and favoring parasite resistant ewes and rams in their selection programs. Both fecal egg counts and FAMACHA© scores can be used to identify sheep with resistant and susceptible genetics. In New Zealand, it is possible to select rams that shed 60 to 70 percent fewer parasite eggs than historical averages. In the US, the National Sheep Improvement program (via Australia's LambPlan) provides EBVs for parasite resistance (fecal egg counts) in Katahdin sheep. Other breeds are now beginning to submit fecal egg count data. EBVs can be calculated for other breeds once fecal egg count data is submitted to NSIP. Scientists are currently looking for genetic markers for worm resistance so that a DNA test could be used to show producers which of their animals are resistant to internal parasites. Proper Anthelmintic Use Anthelmintics are still an important part of parasite control. However, they must be used judiciously ensure effectiveness of treatment and slow down the rate by which worms develop drug resistance. To start with, the weights of sheep and lambs must be known or accurately approximated in order to calculate the proper dosage of medicine. Underdosing results in the survival of worms which are resistant to the anthelmintic used. Underdosing is one of the major causes of increasing anthelmintic resistance. Flocks should be divided into groups for deworming or drenching equipment should be calibrated for the heaviest animals in the group. Oral drenching is the recommended method of treatment for sheep. Oral medications should be delivered over the tongue. If the medicine is deposited into the mouth to stimulate the closure of the esophageal groove and bypass the rumen. If an anthelmintic is more slowly absorbed in the gut, drug levels are prolonged and the treatment may be more effective. Thus, fasting sheep for up to 24 hours may improve efficacy of dewormers, especially when using benzimidazoles and ivermectin. However, water should not be restricted. To prevent the introduction of drug-resistant worms, you should deworm newly purchased animals with drugs from at least two of the three anthelmintic families. Moxidectin should be favored over ivermectin due to its superior potency. Levamisole should probably be the other choice, since widespread resistance is believed to exist in the benzimidazole group of dewormers. After deworming, the animal(s) should be released onto a wormy pasture to help dilute any "super-resistant" worms that may remain in his system. Combination treatments It is now recommended that clinically-parasitized animals (as evidenced by FAMACHA© score, Five Point Check© or other criteria) be given combination treatments. A combination treatment is when you give different drugs to kills the same worms. Treatment is maximized because of the additive effect of the different dewormers. The recommendation is to give the most potent drug from each drug class, usually albendazole (Valbazen®) + moxidectin (Cydectin®) + levamisol (Prohibit® or LevaMed®). Ideally, each drug is dosed using a separate syringe. The drugs should not be mixed because they are not chemically compatible. The drugs are administered sequentially at the labeled dose. The withdrawal period is the withdrawal period of the drug with the longest withdrawal. Anthelmintic resistance It is recommended that producers test for anthelmintic resistance every 2 to 3 years. There are two ways to test for anthelmintic resistance. The primary method is the fecal egg count reduction test (FECRT). Before and after fecal egg counts are compared. An effective treatment should reduce fecal egg counts by 95 percent or more. A low level of resistance is present if egg counts are reduced by 90 to 95 percent. If treatment fails to reduce egg counts by 60 percent or more, drug resistance is considered high. The DrenchRite® assay is another method for determining anthelmintic resistance. The DrenchRite® test determines anthelmintic resistance to all drug classes from a single pooled sample. The University of Georgia College of Veterinary Medicine has the only lab that performs this test in North America. Alternative Dewormers Currently, there is a lot of interest in using "natural" substances as an alternative to synthetic dewormers. Such products include herbal dewormers and diatomaceous earth. Unfortunately, there is no research to indicate that any of these products have a substantial effect on internal parasites in sheep, only testimonials. However, this is an area of increasing research interest and hopefully recommendations will be forthcoming in the years ahead. The exception is copper oxide wire particles (administered as a bolus), which have been shown to reduce barber pole worm infections in sheep (and goats). Copper oxide wire particles are available in bolus form as copper supplements for cattle and goats. The boluses can be repackaged into smaller doses for sheep, usually 0.5 to 2 g. Dosage is based on age, not weight. Lambs should be given a 0.5 to 1 g bolus. Mature sheep can be given a 1 to 2 g dose. Boluses sold for goats should not be used because they contain too much copper for anthelmintic treatment. It is recommended that sheep producers learn the copper status of their farm and sheep before using copper oxide wire particles as a primary method of parasite control. Copper sulfate is a old-time dewormer that was responsible for many sheep deaths. As compared to copper oxide, it is more readily absorbed. It is generally not recommended as a dewormer (for sheep). Nor is it recommended that copper be added to mineral or salt mixtures for sheep. Refugia Worms in "refugia" are those worms which have not been exposed to drug treatment. They include free-living stages on pasture and worms in untreated animals. Refugia are essential to maintaining the effectiveness of anthelmintics and slowing the development of resistant worm populations. To increase refugia, it is suggested that a portion of the flock not be dewormed. Fecal egg counts and FAMACHA© scores can be used to identify which animals do not require deworming. Another strategy for increasing refugia is to return treated animals to a wormy pasture. The reason for this recommendation is because if treated animals are moved to a "clean" pasture, the only worms that will be on that pasture will be resistant to anthelmintic treatment. For similar reasons, it is recommended that sheep not be held in dry lot after treatment. Fecal Egg Counting Fecal egg counting can be important part of an internal parasite control program. Primarily, a fecal egg count will tell you how contaminated your pastures are. Fecal egg counts can also be used to make selection and culling decisions by identifying animals with both high and low egg counts. Probably the most valuable use of fecal egg counts is determining drug resistance. To do your own fecal egg counts, you need a microscope, flotation solution, mixing vials, strainer, stirring rod, slides, and cover slips. You do not need an elaborate microscope. 100X power is sufficient. You can purchase flotation solution from veterinary supply companies or make your own by mixing a saturated salt or sugar solution. Your mixing vials can be jars, pill bottles, film canisters, test tubes, or something similar. You can use a tea strainer or cheese cloth to strain the feces. The stirring rod can be a pencil or craft stick. A McMaster egg counting slide has chambers that making egg counting easier. There are several source of McMaster slides. Identifying Worm Eggs. "Strongyle-type" eggs (Haemonchus, Teladorsagia, and Trichostrongylus) are elliptical or oval, with smooth, thin shells. Nematodirus eggs are the largest Strongyle-type eggs, but eggs of the species in the group cannot usually be identified precisely. Worming recommendations can be based on the quantity of Strongyle eggs. Since fecal counts only estimate the parasite load, there is no clear cut level at which worming is indicated. As a general guide, a level of about 500 eggs per gram of feces would indicate that worming is needed for sheep. A more effective way of deciding when to treat would be to monitor fecals every 4-8 weeks and deworm when there is a dramatic rise in egg counts. Tapeworm eggs are square or triangular. Tapeworm (Moniezia sp.) eggs may be seen in fecal examination but they are in no way indicative of the level of infection. Since lungworm eggs hatch before being passed in the feces the eggs generally are not seen by the flotation method. Nematode larvae, when present in the feces, are indicative of lungworm. Fluke eggs are oval and have a smooth shell with a cap or operculum at one end. Liver flukes are prolific egg producers, but egg counts are not necessarily a good indication of infection levels. Coccidia eggs (oocysts) are very small, about a tenth the size of a Strongyle egg. Coccidia oocysts are passed in the feces of most livestock. Oocysts are only a moderate indicator of level of infection. FAMACHA© The FAMACHA© system was developed in South Africa due to the emergence of drug-resistant worms. The system utilizes an eye anemia guide to evaluate the eyelid color of a sheep (or goat) to determine the severity of parasite infection (as evidenced by anemia) and the need for deworming. A bright red color indicates that the animal has few or no worms or that the sheep has the capacity to tolerate its worms. An almost white eyelid color a warning sign of very bad anemia; the worms present in the sheep's gut are in such numbers they are draining the animal of blood. If left untreated, such an animal will soon die. The FAMACHA© chart contains five eye scores (1-5), which have been correlated with packed cell volumes (percentage of blood made up of red blood cells, also called hematocrit). Animals in categories 1 or 2 (red or red-pink) do not require treatment whereas animals in categories 4 and 5 (pink-white and white) do. Animals in category 3 may or may not require treatment depending upon other factors. Mature sheep in category 3 (pink color) probably do not requiring treatment, whereas lambs or other susceptible animals might require (or benefit from) treatment if they are in category 3. The frequency of examination depends upon the season and weather pattern, with more frequent examination usually necessary in July, August, and September, the peak worm season. The FAMACHA© system results in fewer animals being treated, which slows down drug resistance. It identifies wormy animals that require treatment. Persistently wormy animals, especially breeding rams, should be culled. The process of inspecting the eyes is quick and can be incorporated with other management practices. Proper handling facilities will facilitate the use of the FAMACHA system. The FAMACHA© system is only effective for the barber pole worm and other blood-feeding parasites. It should not be used in isolation. It should be incorporated into an integrated worm control program that includes other management practices, such as pasture rest, good nutrition, multi-species grazing, alternative forages, zero grazing, and genetic selection. FAMACHA© should only be used by properly trained individuals. To get a FAMACHA© card, producers must take an approved training. It is now possible to receive online training. Five Point Check© The same South African researchers who developed the FAMACHA© system have developed the Five Point Check© for targeted selective treatment of internal parasites in small ruminants. The Five Point Check© expands the utility of the FAMACHA© system by incorporating other check points to encompass the symptoms and deworming need for other internal parasites of economic significance. It is also useful for making deworming decisions for animals with FAMACHA© scores of 3. A happy sheep is a productive sheep The Happy Factor™ is another decision support model that has been used to determine which animals would benefit from anthelmintic treatment. It uses performance-based criteria. Animals which do not reach predicted target weights are dewormed. The Happy Factor™ is especially adaptable to automated weighing and drafting systems.

SOME KEY POINTS Drugs should be used in accordance with the manufacturer's label or product insert. All antibiotics require a veterinary prescription. Only a licensed veterinarian has the legal right to use or prescribe drugs extra label. Anthelmintics (dewormers) should be administered according to the recommendations of the American Consortium for Small Ruminant Parasite Control (ACSRPC). Withdrawal periods should be strictly adhered to. A drug is a product used to treat or prevent an illness. Drugs can play an important role in preserving the health of individual sheep and the flock as a whole. However, they need to be used in a responsible manner, and producers should strive to minimize drug use and not use drugs in place of good management and feeding practices. In the US, drugs are approved (for use) by the Food & Drug Administration (FDA). Some drugs may be purchased over-the-counter (OTC), without veterinary approval, whereas other drugs require a veterinary prescription (Rx). OTC drugs are available from from many sources, including veterinarians, feed and farm supply stores, and via the internet. Prescription (Rx) drugs can only be purchased and used under the guidance of a licensed veterinarian. Usually, they must be purchased from a veterinarian. Extra-Label Drug Use It goes without saying that all drugs should be used in accordance with the manufacturer's label or product insert. Using a drug in any manner that is not specified on the label requires "extra-label" drug use and must meet the requirements of extra-label drug laws. Only licensed veterinarians may use or prescribe drugs extra-label. Extra-label is the proper term. Off-label is not a legal term. Extra-label drugs use requires valid veterinarian-client-patient-relationship (VCPR). Producers are not supposed to use drugs extra-label, even if they can purchase them OTC. In addition to using a drug that is not labeled for a particular species or class, giving a higher dosage of an "approved" drug or administering it in a different manner (SQ vs. IM) also constitutes extra-label drug use. Extra-label drug use is only allowed when the health of an animal is threatened and there is no other treatment alternative. Unapproved drugs cannot be used "off-label" to improve performance or control reproduction. As compared to cattle, horses, and swine, far fewer drugs are approved by FDA for use in sheep. The Minor Use Minor Species (MUMS) law is supposed to make it easier for drug companies to get approvals for sheep. Withdrawal periods The withdrawal period is the amount of time it takes for a drug to "clear" the animal's system, so that drug residues do not remain in the tissues or milk. Every federally-approved drug or animal health product has a withdrawal period printed on the product label or package insert. When used according to the label, most meat withdrawal periods range from 0 to 60 days. Withdrawal periods may be different for milk and in some cases, the product may not be approved for use in dairy females. Withdrawal periods can be an important consideration when choosing which drug to use to treat a sick animal. Not all drugs have withdrawal periods. Withdrawal periods should be extended when the drug is not used in accordance with the label. In these situations or at any time a producer is uncertain as to the withdrawal period of a certain drug, a veterinarian should be consulted. Veterinarians have access to the Food Animal Residue Avoidance Database (FARAD) which provides withdrawal information for drugs that are used in an extra-label manner. Extra-label withdrawal periods may also be available in the scientific literature. Antibiotics An antibiotic is a medication used to treat or prevent bacterial infections. When used properly, antibiotics are powerful tools for maintaining healthy, productive animals. Not all antibiotics work the same and are effective against the same bacteria or diseases. Sometimes, laboratory cultures are necessary to determine which antibiotic(s) should be used to treat a specific disease. Producers should limit antibiotic treatment to those animals that are sick or at-risk of becoming sick. If antibiotics are not used properly, the opportunity for resistant bacteria to develop increases needlessly and can compromise future antibiotic therapy. Detailed and accurate records of antibiotic treatments and outcomes should be kept. The following table lists the antibiotics that are currently FDA-approved for use in sheep and lambs (in the US). The approved antibiotics vary in their use. As of January 1, 2017, all antibiotics deemed important to humans and mixed in the feed require a veterinary feed directive (a written order). Antibiotics that are put in the drinking water now require a veterinary prescription. Aureomycin is the only antibiotic currently approved for use in the feed for sheep. Under the new regulations, aureomycin may be fed at a rate of 80 mg per head per day for prevention of abortion caused by campylobacter spp. Antibiotics can no long be fed to lambs to improve growth and feed efficiency. When deemed necessary, the following antibiotics may be prescribed for use in sheep by veterinarians (only). When using drugs extra-label, you cannot assume the withdrawal period indicated on the label is adequate for sheep. LA-200® is a long-acting broad spectrum antibiotic. Nuflor® is commonly used to treat pneumonia. Zactran® has proven to be effective at eradicating foot root from a flock. Sub-therapeutic use of antibiotics Sub-therapeutic means below the dosage level to treat disease. Sub-therapeutic levels of antibiotics have been fed to sheep and/or lambs to prevent disease outbreaks. Feeding antibiotics to ewes during late pregnancy can help to control abortions. When a ewe has been assisted in the delivery of her lamb(s), it is recommended that she be given an antibiotic to prevent uterine infections. Antibiotic use is prohibited under USDA certified organic standards of livestock and meat production. While it is not recommended that treatment be withheld from a sick animal, if an animal is treated with an antibiotic, it can no longer be marketed as certified organic. Its milk or dairy products cannot be used to make organic products. Anthelmintics An anthelmintic is a medication that kills worms. It is also called a "dewormer" or anti-parasitic drug. Anthelmintics are available as drenches, boluses, pastes, injectables, pour-ons, and as products that you mix with the feed. All anthelmintics may be purchased over-the-counter. While different formulations are available OTC, it is recommended that sheep and lambs always be treated with oral products: drenches (and boluses). These formulations are usually more effective and less likely to promote drug resistance. In the U.S., they are the only products FDA-approved for use in sheep and lambs. Several new anthelmintics including Zolvix® (monepantel) and Startect® (derquantel + abamectin) are available for use in other countries. When treating sheep for internal parasites, you need to make sure you give them the proper dose. Underdosing promotes the development of drug-resistant worms. Anthelmintics should be delivered over the sheep's tongue using a syringe with a long metal nozzle. Injectable dewormers should not be squirted in the sheep's mouth, nor should pour-on dewormers be administered orally. It is not recommended that sheep and lambs be dewormed on a regular or scheduled basis or that all animals in a group be treated with an anthelmintic. Targeted selective treatment (TST) should be integrated with other worm control practices such as pasture rest and rotation, mixed species grazing, alternative forages, zero grazing, and genetic selection. It is now recommended that clinically-parasitized animals be given combination treatments. While combination products are available in other countries, in the US, this requires purchasing and administering each anthelmintic separately and singly. Anthelmintics should not be mixed, as they are not chemically compatible. When giving combination treatments, a full dose of each anthelmintic should be administered. The dewormers can be given one after the other. The withdrawal period of the dewormer with the longest withdrawal should be followed (usually Cydectin®). Under USDA organic standards, an anthelmintic may only be given to a ewe during the last third of gestation. Animals destined for slaughter cannot be dewormed. While it is not recommended that treatment be withheld from a clinically-parasitized animal, if it is treated, it can no longer be sold as certified organic, even if proper or extended withdrawal periods are observed. Copper oxide wire particles (COWP) offer a treatment alternative to synthetic dewormers. While copper sulfate is a historical dewormer which sometimes caused copper toxicity in sheep, COWP are a less absorbable form of copper that have demonstrated efficacy against barber pole worm infections in sheep and goats. More recent research has shown that COWP when used conjunction with a commercial dewormer (e.g. Valbazen®) can increase treatment efficacy. COWP are available as a copper supplement for cattle (12.5 and 25 g) and goats (2 and 4 g). The boluses should be repackaged into smaller dosages for sheep and lambs. Dosage is based on age not weight. Typically, lambs are given a 0.5 to 1 g, while ewes are given a 1-2 g dosage. It is recommended that sheep producers learn the copper status of their animals and farm before including COWP in the their internal parasite control program. Coccidiostats A coccidiostat is a compound added to animal feed to inhibit or delay the development of coccidia, a protozoan parasite that causes scouring and damage to the lining of the small intestines. Ionophores are classified as antibiotics by FDA; however, their use was not affected by the 2017 Veterinary Feed Directive, as they are not medically important to people. In the US, Bovatec® (lasalocid) is approved as a coccidiostat for sheep maintained in confinement. Twenty to 30 grams of Bovatec® may be mixed in a ton of sheep feed. Ionophores are not permitted under USDA organic standards, even though there is no slaughter withdrawal and ionophores are not used in people. Deccox® (decoquinate) is also approved as a coccidiostat for young sheep. It can be mixed in the feed or milk replacer. Rumensin® (monensin) is not approved for use in sheep, but can be prescribed by a veterinarian extra-label, if the other coccidiostats are determined to be ineffective. Rumensin® is toxic to members of the equine family and can be toxic to sheep if it is not mixed properly. Corid® (amprolium) is the only coccidia drug that can be used as both a preventative and treatment for coccidiosis. It can be mixed in the drinking water to prevent outbreaks of coccidiosis or it can be administered to individual animals at a higher dose to treat clinical coccidiosis. It is a better treatment than preventative. Corid has a unique mode of action. It mimics thiamine (vitamin B12). When the coccidia ingest Corid, they experience thiamine deficiency and starve from malnutrition. Sulfa drugs are also used to treat coccidiosis. Like Corid®, sulfa antibiotics are put in the drinking water or administered as a drench. Corid® and sulfa drugs are not FDA-approved for use in sheep and goats. Their use requires veterinary approval. While Corid® was not affected by the 2017 Veterinary Feed Directive, the marketing status of sulfa antibiotics, such as Di-Methox® changed from OTC to Rx. Sulfa antibiotics must now be obtained from a veterinarian. In other species and countries, there are several other options for preventing and treating coccidiosis. Baycox (toltrazuril) is a one-dose oral treatment for control of coccidiosis. Ponazuril, a derivative of toltrazuril is also used to treat coccidial infections. In the U.S., it is marketed as Marquis® (Rx for horses). Vecoxan® (diclazuril) is another oral suspension that can be used to prevent or treat coccidiosis. Its advantage is that it has a zero day withdrawal, whereas toltrazuril has a 42 day withdrawal period for lambs. Vaccines (biologics) A vaccine is a biological preparation that is used to establish or improve immunity to a particular disease. Sheep and lambs are commonly vaccinated for clostridial diseases and other diseases as situations warrant. A vaccine stimulates the body's defense system to build immunity to a particular disease, by exposing the animal to either the live organism in a safe form (e.g. sore mouth) or to a killed or inactivated organism or part of an organism (e.g. clostridial diseases). Vaccinations in an annual program require an initial dose the first year followed by a booster to provide maximum protection. Anti-toxins can be used in disease outbreaks or to provide immediate short-term immunity. In sheep, the tetanus anti-toxin can be given to lambs at the time of docking and/or castration, especially if the lamb's dam was not vaccinated. Most vaccines are administered by giving an injection under-the-skin (subcutaneous). A few vaccines are administered intramuscularly and occasionally some are given topically (e.g., soremouth vaccine) or intranasally. If there is a choice, subcutaneous injections should be given, as this causes less damage to muscle tissue. It is important to always follow label directions when giving vaccines. Proper handling of vaccines is important to prevent vaccination failure. Vaccines are sensitive to light and should be refrigerated. Vaccines are not always effective in the face of an overwhelming disease challenge. A clean needle should always be used to draw vaccine out of a bottle. Ideally, a clean needle is used for each animal. Unlike antibiotics and anthelmintics, all USDA and third party labeling and certification programs allow the use of vaccines for disease prevention. Other treatments and medications Sometimes other injectables are used to treat health problems in sheep. For a producer to administer many of these injectables, the product(s) must be purchased from and used under the guidance of a licensed veterinarian. Oral products are used to treat disease conditions or provide supportive therapy to diseased or stressed animals. Unlike many of the injectables listed above, they can usually purchased OTC and be used without veterinary oversight. Orals are commonly used to treat sheep with digestive upsets or to provide supplemental nutrition to sick or stressed animals. Various products found around the house can often be used to treat sheep and lambs for simple health problems. In some cases, they can replace more expensive commercial products or supplements. Like the oral treatments in the table above, they are used primarily to treat digestive upsets and provide supplemental nutrition to stressed animals. Household remedies are used on a trial-and-error basis. Generally, there is no scientific basis for their use and they may not be as effective as the commercial products. Administering medications and other treatments Medications do little good, unless they are administered properly. You can also kill or cause permanent damage to an animal if you do not administer the medication properly. Before any treatments are given, the animal must be properly restrained. Injections Only clean needles and syringes should be used for giving injections. A clean needle should be used to draw solution out of a bottle. The recommended length and gauge of the needle will depend upon the size of the animal and the thickness of the solution. Generally, use the smallest gauge needle that is suitable. A 1/2 inch 18 gauge needle is ideal for vaccinating. Needles are inexpensive and should be disposed of after use. The best place to give subcutaneous injections is in the loose skin of the axilla (armpit) or over the ribs. Intramuscular injections should be given in the neck muscle. While the large muscle mass of the thigh may seem like the logical place to given an intramuscular injection, this will cause damage to the meat. When repeating injections, use the opposite side of the animal for the second injection. Never inject more than 5 ml at one site. Very few drugs need to be given intravenously; although the same technique is used to collect blood samples. It takes some skill to locate a vein (usually the jugular) and keep the needle in place while the drug is being given. IV drugs should be injected slowly, as animals will react very quickly, with the drug dispersing to all the tissues and going straight to the heart. An intraperitoneal injection should only be attempted by a skilled person who is familiar with anatomy, as improper technique can cause peritonitis. An intraperitoneal injection is most commonly given to a hypothermic lamb. While the lamb is hanging from its front legs the needle is inserted perpendicular to the skin, approximately 1 inch to the side of and 1 inch caudal to the navel. Intramammary "injections" (infusions) are given using a long-neck tube instead of a needle. The tube is delicately inserted into the teat sphincter. It goes without saying that the end of the teat should be cleaned before inserting the tube into the teat canal. If the animal receiving the injection will be used for meat, make sure you check the withdrawal times. Slaughter withdrawal times for most vaccines are 21 days. Meat withdrawal periods for antibiotics and other injectables vary. Be sure to check the label or consult with a veterinarian. When a drug is used extra label, its withdrawal time may be longer than what is listed on the label for the approved species. Sharps Sharps should be properly disposed of. Sharps include needles, syringes, scalpel blades, slides, pipettes, and anything else that can puncture. Sharps should be collected on the farm in a rigid, puncture-resistant container with a screw-on or tightly secured lid. Containers should be visibly labeled as biohazardous material. Once full, they should be taken to an approved collection facility for medical or veterinary waste. Expired and unused medicine should be disposed of in the same manner as sharps. Drenching Drenching is when liquid medicine is poured down the animal's throat. An oral syringe with a long metal nozzle should be used for drenching. Automatic drench guns can be used for large numbers of animals. To drench, you should place a hand under the animal's head and tilt it slightly to the side. The gun nozzle should be placed in the gap between the molar and incisor teeth and then over the back of the tongue. If the medicine is placed in the mouth, it may by-pass the rumen as it escapes down the esophageal groove. The animal should swallow before the gun is removed. Covering the animal's nostrils will encourage swallowing. Poor drenching technique can cause aspiration pneumonia (an infection of the lungs caused by breathing in foreign material). To prevent medicine from entering the animal's bronchial tubes or lungs, the animal's head should be held horizontally. It should not be tilted up. Drench guns should not be forced down the animal's throat. Drenches should not be administered faster than the animal can swallow. Giving boluses Sheep and lambs can be given boluses (or capsules) by using a balling gun. A balling gun is a plastic or metal tube with a capsule holder on one end and a plunger on the other end (to eject the capsules). Balling guns are available in different sizes. Young animal balling guns are suitable for sheep and lambs. The balling gun is inserted into the animal's mouth in the same manner as drenching. The plunger should not be depressed until the end of the gun is over the base of the tongue. Otherwise, the pill may be chewed or spit out by the animal. Quality and Safety Assurance The American Sheep Industry Association (ASI) began development of an industry-wide quality and safety assurance program in 1991. Quality assurance programs provide assurances to consumers that products have been produced in accordance with certain standards, including the proper use of animal health products. USDA and third party certification groups that do not allow the use of antibiotics, anthelmintics, coccidiostats, and other animal health products do so without any scientific basis or contribution to animal welfare. As with people, sometimes drugs are necessary to maintain the health and well-being of farm animals. It is safe to consume the milk and meat from treated animals, if proper withdrawal times have been observed. Antibiotic resistance There is widespread disagreement with regards to animal agriculture's role in the development of antibiotic-resistant bacteria. Information on the subject is often biased and sensationalized. Due to its small size and diversified production systems, the sheep industry likely has no contribution to the development of resistant bacteria. Yet regulations which restrict antibiotic use are especially detrimental to minor species like sheep, as there are few products FDA-approved (for sheep) and a dearth of veterinarians willing to work with small ruminants. Increased regulations will significantly reduce the health and welfare of sheep and lambs, while likely having no effect on the development of resistant bacteria.

SOME KEY POINTSThere may be things on your kitchen shelves, in your medicine cabinet, or readily available at local stores that can be used to prevent and/or treat disease in sheep/goats. Most home remedies should be considered emergency aides rather than primary treatments.Research is usually lacking; evidence of treatment efficacy is primarily anecdotal. Natural alternatives to antibiotics and other drugs are being sought.There are numerous natural and home remedies -- things on your kitchen shelf, in your medicine cabinet, or readily available at local stores -- that are often used to prevent or treat disease conditions or provide supportive therapy to sheep/goats. While the benefits may be mostly anecdotal and research is ongoing or lacking, they are frequently used by producers -- and might help.Activated charcoal Activated charcoal is a powder comprised of wood, bamboo, coal, or coconut shells that have been burned at a very high temperature. Activated charcoal is a proven supplement that benefits the healthy gut of animals. It is used in animal feeds as an antidote for poisoning and to control diarrhea. Activated charcoal can be given to individual animals who have consumed toxins or to help control their diarrhea. Activated charcoal is available as a powder, gel, or supplement (for feed). Aspirin Aspirin (or ibuprofen) can be an option for those who don’t have prescription pain meds/anti-inflammatory drugs on-hand. Aspirin is a non-steroidal anti-inflammatory drug used to treat pain, fever, and inflammation. It can be given to sheep/goats for these same reasons. Some producers opt for baby aspirin, especially for smaller animals. There are also aspirin formulations (boluses and powder) commercially available for livestock, though not all are approved for sheep/goats. While oral aspirin has not been found to be an effective pain reliever when administered immediately after application of rubber rings (for docking/castrating), its use may warrant further investigation.Antacids Over-the-counter antacids, such as Mylanta® and Tums®, can help to neutralize acid in the gut. They can be used to treat bloat, acidosis, and other digestive upsets in sheep/goats. Apple Cider Vinegar While all sorts of claims have been made about apple cider vinegar, few have been substantiated. Regardless, apple cider vinegar (raw, unfiltered) is a source of nutrients, including probiotics, that can be given to animals that are off-feed or require a nutritional boost. Some producers provide apple cider vinegar on a regular basis to their animals, touting the “potential” health benefits. Apple cider vinegar is commercially available in gallons and barrels. You can improve its palatability by mixing it with molasses.Baking Soda Baking soda (sodium bicarbonate) helps to neutralize acid in the gut. As such, it is a common treatment for bloat, acidosis, and other digestive upsets. It is the recommended treatment for floppy kid syndrome and “big and dumb” syndrome, both of which are characterized by a build-up of lactic acid in young kids/lambs. Some producers offer baking soda free choice to their sheep/goats as a preventative for acidosis and/or bloat. In fact, free choice baking soda is a good idea for any sheep/goat that is fed a lot of grain. It can also be incorporated into the ration as a rumen buffer. Feed grade sodium bicarbonate is available (in bags) from most feed stores. Beer Beer (especially dark) has a long history of being used for livestock. Beer is given to animals that are off-feed. It is a source of fluids, energy, vitamins, and minerals. The yeast in beer may help to restart the rumen. Beer is sometimes given to a sow after she has finished giving birth to her piglets. Supposedly, the beer helps the sow relax and let her milk down. Benadryl® Benadryl® is an over-the-counter anti-histamine used to relieve symptoms of allergy, hay fever, and common colds. It is sometimes used to treat allergic reactions in sheep/goats. Castor Oil Castor oil is a vegetable oil pressed from castor beans. Besides being an energy source, castor oil can be used to treat various metabolic problems in sheep/goats, including acidosis, bloat, and constipation (in young lambs/kids). It is often included in homemade “colostrum” recipes for its nutritional value and laxative effect. Cod liver oil Cod liver oil is a dietary supplement derived from cod fish. It is a source of omega-3 fatty acids and vitamins A, D, and E. It has been used as a nutritional supplement for animals. It is sometimes added to homemade “colostrum” recipes. ColaSome farmers have used sugary soft drinks as a home remedy for pregnancy toxemia: low blood sugar (hypoglycemia) and high ketone levels (hyperketonemia). Soft drinks contain high fructose corn syrup which is rapidly absorbed. Soft drinks should be considered an emergency aid rather than a primary treatment.Corn Oil Corn oil is a dietary source of fat. It can be added to the ration to increase energy intake. It can also be given to animals that are off-feed or require an energy boost. If propylene glycol is not available, corn oil can be given to ewes/does in the initial stages of pregnancy toxemia (ketosis). Corn oil is commonly included in recipes for homemade “Nutri-Drench.”Corn Syrup Corn syrup is different from corn oil. It is a sweetener. It consists of half fructose and half dextrose (chemically identical to glucose). It can be given to ewes/does in the early stages of pregnancy toxemia (ketosis). Corn syrup is commonly included in recipes for homemade “Nutri-Drench.” Karo® syrup is a commercial product of corn syrup. Diatomaceous earthDiatomaceous earth (DE; also known as Diatomite) is an off-white, talc-like powder that is the fossilized remains of tiny aquatic organisms. DE has many uses. It is an anti-caking agent used in feed rations. It is used as an insecticide; DE products are registered for use against many pests. What DE is not is an effective dewormer. Despite testimonials, there is no scientific proof that DE has any effect on worm burdens in livestock. More studies are needed to determine if DE could have preventative properties instead or other health or production benefits to livestock.Ensure®Ensure® provides nutrition in a tasty “shake.” It is often recommended for older people or those who need to gain weight. Ensure can provide a similar nutritional benefit for sheep/goats. Generic brands are less expensive than Ensure® and probably just as good. Essential Oils Essential oils are compounds extracted from plants. They have many potential benefits. Peppermint and tea tree oil have been used to treat mastitis. Tea tree oil has been used to treat hoof disease. Oregano oil is being evaluated for its potential to prevent coccidiosis. Some essential oils are “hot” and need to be diluted with carrier oils or water before they can be used. Be sure to do research before using essential oils. An increasing number of commercial products contain essential oils. Research is currently underway to determine the benefits of different essential oils or mixtures on livestock health and productivity.GarlicGarlic products have the potential to improve ruminant growth and health, reduce methane emissions, and improve product quality. Garlic is a rich source of essential nutrients and phytochemicals. It is available in many forms. Studies are currently underway to evaluate the benefits of adding garlic to ruminant diets. Garlic is also touted as a “natural” dewormer. Unfortunately, there is little evidence that it kills worms. Perhaps it acts more as a preventative.Gatorade® Gatorade® is an electrolyte-restoring liquid (a “sports drink”). It can be used to rehydrate sheep/goats. It is commonly given to stressed animals. In fact, Penn State research showed that offering livestock Gatorade® helped to reduce weight loss during transportation. Gatorade® is an option when commercial electrolyte solutions are not on-hand. Honey Honey is a sweet food substance made by bees. It is an energy source for sheep/goats. It can be given to animals that are off-feed or require an energy boost. Research is currently underway to evaluate the potential benefits of bee products on livestock nutrition and health. JelloJello (gelatin) is a sometimes treatment for diarrhea (scours). It can also make bitter tasting medicines more palatable. For example, Jello is often mixed with ammonium chloride (to treat urinary calculi) and DiMethox® (to treat coccidiosis). Jello is also sold as a supplement for promote overall health in livestock.Kaopectate® Kaopectate® is an over-the-counter treatment for mild diarrhea. It is commonly used to treat non-infectious causes of diarrhea (scours) in sheep/goats. It can be purchased commercially (in larger quantities) as Kaolin Pectin. Kefir Kefir is a fermented milk drink, especially popular in the Middle East. Kefir contains more probiotics than yogurt. Kefir is commonly given to stressed animals to improve gut health. It may be most beneficial for livestock still on milk diets or transitioning off milk. Research is currently underway to determine the potential benefits of Kefir for livestock. Milk of Magnesia Milk of Magnesia is an over-the-counter antacid and laxative. It is used to treat various metabolic problems in sheep/goats, including bloat, acidosis, and constipation (in young lambs/kids).Mineral Oil Mineral oil is a must-have on any sheep/goat farm. It is a tasteless, odorless oil that can be used to treat various metabolic problems, including bloat, acidosis, and constipation. It can also help to clear intestinal impaction or obstruction. Mineral oil is a laxative that lubricates the intestinal tract. When administering mineral oil, care must be taken to avoid aspiration into the lungs. Larger quantities of mineral oil should be administered using a stomach tube. Gallon jugs of mineral oil are commercially available from livestock supply companies. MolassesMolasses is a common feed ingredient (wet or dry). It is usually added to rations to increase palatability and remove dust. Molasses is an energy source that can be given to animals that are off-feed or in need of an energy boost. It can be used to treat early-stage pregnancy toxemia (ketosis). Molasses can improve the palatability of other over-the-counter remedies. It is often included in recipes for homemade “Nutri-Drench.” Larger quantities of molasses can be purchased from farm or feed stores or stores that supply hunters.Pedialyte® Pedialyte® is an electrolyte drink for children. It can be used to rehydrate sheep/goats, especially young ones. Lambs/kids with scours often become dehydrated, regardless of the cause of the diarrhea, and need fluid replenishment. Pedialyte® is an option when commercial electrolyte solutions are not on-hand. Plus, it’s available in smaller amounts, more suitable for sheep/goats. Pepto Bismol® Pepto-Bismol® (bismuth subsalicylate) is commonly used to treat non-infectious causes of diarrhea (scours) in sheep/goats. Kaolin Pectin or Bismusal is sold commercially as an anti-diarrheal drug for livestock. It is similar to Pepto-Bismol®. Red wineRecent research and veterinary anecdotes indicate that red wine may be a natural, sometimes superior treatment for ketosis, compared to traditional treatments like propylene glycol. Research has been done with dairy cows. Triple Antibiotic Triple antibiotic ointment is an over-the-counter antibiotic that can be used to heal and treat wounds and infections, including pink eye. It contains three antibiotics (neomycin + polymyxin + bacitracin); hence, its name. It comes in a tube and is relatively inexpensive.Vegetable OilBesides being a dietary source of fat (energy), vegetable oils are used to treat metabolic problems in sheep/goats, including bloat and acidosis. Vitamin C While some producers use vitamin C (ascorbic acid) as an alternative treatment for the early stages of urinary calculi, there is no proof that it helps. The idea is that vitamin C may help to acidify the urine and dissolve the stones. Vitamin C has also been used in the prevention and treatment of mastitis. Animals with mastitis are often deficient in Vitamin C. Vitamin C is usually delivered via fresh fruit or vitamin C tablets or powder. It is also available as an injectable. Sheep/goats normally do not have a dietary requirement for vitamin C because they manufacture it as part of their normal metabolism. WD-40® There is some evidence that WD-40® (a penetrating” oil) may hasten the healing of lesions caused by soremouth (orf). The ether may break down the lipid in the virus. While soremouth is a self-limiting disease, it can cause production losses and prevent timely sale and exhibition of animals. Sheep/goat owners that have soremouth on their farms should consider timely vaccination. YeastYeast has been part of the human diet for thousands of years. In animal feed, yeast products have been used for over 40 years. Not all yeasts are the same. Yeast feed falls into two categories: live yeast probiotics (called direct-fed microbials) and prebiotics, which are non-viable yeasts or fractions of the yeast cell. Yeast optimizes digestive efficiency. Yeast products are used as a surrogate for livestock antibiotics. They are most beneficial for animals under stress or at risk of disease. Research continues to determine how to best use yeast products in livestock management.Yogurt Yogurt is a food produced by the bacterial fermentation of milk. It is a source of probiotics. Yogurt is commonly given to stressed animals. It helps to stimulate appetite and restore gut health. Many producers give it to animals with diarrhea (scours). Yogurt is oftentimes added to milk replacers to reduce the risk of abomasal bloat. When adding yogurt to milk, it is important not to feed the milk right away, as the bacteria need time to multiply. In addition to store-bought yogurt, you can make your own yogurt from cow, goat, or sheep milk. Commercial probiotics are available from livestock supply companies and feed stores. There are also probiotic strains of silage inoculants. It is likely that future research will determine more precisely the role of probiotics (including yogurt and Kefir) in animal health and nutrition, as animal industries look for cost-effective “replacements” for antibiotics. Questions regarding natural and home remedies and their use should be directed towards veterinarians and/or ruminant nutritionists. SOME SAMPLE RECIPESHomemade Nutri-drench 1 cup corn oil 1 pint molasses 1 pint Karo® syrup Homemade Electrolyte Solution 2 teaspoons baking soda 2 teaspoons salt ½ cup molasses or raw honey 4 quarts warm water Homemade “colostrum” recipe* 3 cups milk 1 egg 1 tablespoon sugar, honey, or corn syrup 1 tablespoon cod liver oil (optional) *Provides nutrients, but not antibodies. Sources of the recipes are unknown. They are shared on the internet in multiple places.