Coccidiosis
Coccidiosis is a diarrhea disease caused by any of a number of protozoan parasites of the Eimeria species. Coccidiosis is likely the most common cause of diarrhea in young kids but can affect older animals. Stress, weather changes, weaning, diet changes, and kidding can all bring about the onset of this disease. Young kids 1 to 4 months of age appear most susceptible.
The coccidia causing diarrhea in goats are host specific meaning that they rarely infect other animal species. Thus, coccidia that affect goats will not infect sheep and vice versa. Transmission is oral. The coccidia shed eggs or oocysts in the feces that must sporulate outside of the animal to become infective. Sporulation occurs under moderate temperatures and moist conditions. The oocysts can survive a wide range of temperatures and live for years in the environment. The life cycle for coccidia under ideal conditions is two to three weeks.
Constant exposure to low levels of coccidia can confer some level of immunity to the animal. However, consumption of large numbers of coccida at one time can overwhelm the immune system. Further, each individual species of Eimeria is independent of the others and there is no cross-immunity. An animal with immunity to one type of Eimeria can still develop coccidia from exposure to a different species.
Signs and symptoms
Coccidia enter the body and destroy cells lining the intestinal tract causing that animal to develop watery diarrhea, usually without blood. Other signs include straining to defecate, decreased appetite, dehydration, weight loss, and anemia. Some animals may suffer rectal prolapse. In acute cases, kids can die in 1 to 2 days and losses can be severe. Older animals may have diarrhea for up to 2 weeks before recovering. Some animals suffer chronic infection having intermittent diarrhea and poor growth. Coccidia can be seen when performing a fecal egg count but presence of coccidia does not mean the disease is occurring.
Treatment, prevention, and control
Treatment includes giving fluids and coccidiostats. Coccidiostats have little effect upon the existing infection but can reduce the spread of the disease. In addition to preventing coccidiosis, coccidiostats also confer the advantages of increased feed efficiency and enhanced growth. However, continuous feeding of coccidiostats increases the risk for drug resistance to develop. Coccidiostats are normally fed during periods of extreme stress and wet conditions. If feeding coccidiostats for prolonged periods, fecal exams should be done to evaluate the drug’s efficacy.
Coccidiostats approved for use in the U.S. include decoquinate (Deccox, 0.5 mg/kg body weight or 13 – 91 grams/ton feed) and monensin (Rumensin, 10 – 30 grams/ton feed). Amprolium (Corid, 50 mg/kg body weight per day) is not approved for use in goats and can only be used in the context of a valid veterinarian-client-patient relationship. Amprolium should only be fed for periods of 3 to 4 weeks. Prolonged feeding can predispose kids to polioencephalomalacia (PEM). Lasalocid (20 – 20 grams/ton feed) is approved for sheep but not goats. Be aware that both lasalocid and monensin are toxic to horses.
Prevention is accomplished by improved sanitation, not overcrowding animals, minimizing stress, and a good nutrition program.
Cryptosporidiosis
Cryptosporidiosis is a protozoan-caused diarrhea disease in kids. Occurrence is more common in kids raised in a barn or in confinement than kids raised on pasture. The infective agent is Cryptosporidium parvum. Unlike coccidia that need to sporulate outside the animal to become infective, cryptosproridium sporulate inside the animal. This means that the protozoa can be self-sustaining in the animal resulting in severe disease. This also means that the feces of infected animals contain sporulated eggs that can directly infect other goats thereby quickly spreading the disease. Further, the disease is zoonotic and people can become infected from handling feces.
Signs and symptoms
Affected kids are usually less than two weeks of age. Diarrhea is bright yellow and watery and can last from 2 to 14 days. Kids are dehydrated, have decreased intake, poor growth, and depression. The diarrhea ranges from self-limiting to very severe and fatal. Recovered animals frequently suffer relapses.
Treatment, prevention, and control
Kids should be isolated, provided fluids, and kept warm. Any pens holding diseased animals should be cleaned. The organism survives in the environment and is resistant to many disinfectants; however, a 5 to 10% ammonia solution is effective. Proper sanitation and reduced fecal contamination of feed and water are preventive measures. Decoquinate (Deccox) at 2.5 mg/kg orally may be useful in prevention.
Stomach and intestinal worms
There are a number of stomach and intestinal worms that can affect goats. The most common and devastating in terms of death, lost productivity, and cost is the barberpole worm (Haemonchus contortus). A complete discussion of this and other internal parasites as well as chemical and other control methods can be found in the chapter on Internal & External Parasites. Anthelmintic drugs and dosages and procedure to perform a fecal egg count can be found in the Meat Goat Herd Health – Procedures and Prevention chapter.
Mange
Mange is caused by mites feeding on the skin of affected animals. Three types of mange that affect goats in the U.S. are psoroptic, demodectic, and chorioptic. Psoroptic mange (ear mange) is caused by the mite Psoroptes cuniculi and usually infests the ears but can spread to the head, neck, and body. Demodectic mange is caused by Demodex caprae that infests skin glands and hair follicles of the limbs, face, and back. Chorioptic mange is caused by the mite Chorioptes caprae and usually affects the scrotum, lower limbs, and abdomen. Transmission is usually from animal to animal though these mites can live in the environment for limited periods of time, up to 3 months for C. caprae, for example. Some goats may be unaffected carriers of the mites. Saliva from mite bites causes intense inflammatory reactions in the skin resulting in skin lesions and hair loss.
Signs and symptoms
In demodectic and chorioptic mange, goats will develop blisters or scabs on areas affected by the particular mange mite. Hair loss is common and the skin on the back, sides, and limbs of the animal may become crusty in appearance. Goats will scratch removing scabs and leaving a wound that is susceptible to secondary bacterial infection. In psoroptic mange, animals will shake and scratch their head, sometimes using their hind foot. Hair loss around the ears is common. Mange occurrence is most severe in fall and winter. In all cases, animal productivity will decline.
Treatment, prevention, and control
Isolate affected animals. Topical treatments include dips or thorough sprays (coumaphos 0.3%, lime sulfur 2%, and phosmet 0.15 to 0.2%) that should be done at weekly intervals. Commercial products are available that contain these ingredients. Ivomec or Cydectin injections (0.2 mg/kg body weight) can be done at weekly intervals. For psoroptic mange, any products approved for sheep will work with goats. Another alternative is to use a louse or ear mite external medication, such as used with dogs. Lactating dairy goats should be treated only with lime-sulfur solution. If necessary, the animals can be treated using sprays or dips containing organophosphates (diazinon, metrifonate, propetamphos) or pyrethroids (deltamethrin, flumethrin) as permitted.
Chorioptic mange
Lice
Lice infestation is most common in winter months when animals are closely quartered due to outside temperature and the feeding practices used. Both biting lice (Bovicola caprae, B. limbatus and B. crassipes) and sucking lice (Linognathus stenopsis and L. africanus) affect goats. L. africanus is probably the most important sucking louse for goats, attacking anywhere on the body. Lice suck blood and can cause severe anemia. They are spread by direct contact or by contact with contaminated areas of the environment.
Signs and symptoms
Goats will be itchy, have patches of bare skin from hair loss, lose weight, and suffer from anemia in severe cases. Lice can be seen crawling on the skin of the animal.
Treatment, prevention, and control
Treating the environment surrounding the goats to try and rid the area of lice is difficult. Treatment of affected animals includes using dips, sprays, or dusts. Commonly used products are coumaphos (0.125% spray or 0.5% dust), malathion (0.5% spray or 4% dust), and permethrin sprays or pour-on products. Ivomec or Cydectin injections (0.2 mg/kg body weight) can be used against sucking lice. They have limited effectiveness against biting lice. Treat animals at 2 week intervals for at least 2 treatments to ensure that lice emerging from eggs are killed.
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