Posted by Dr. Sara Barber on June 26 2009 10:51
Review of Herd Health Recommendations
Prevention is the name of the game when it comes to disease prevention in sheep.
There are several reproductive diseases are a common cause of abortion in sheep. Campylobacter fetus (Vibrio) causes abortions in late pregnancy. Vibrio is commonly transmitted by ingestion of contaminated feed or contact with an infected fetus. These abortions occur 7-25 days post-infection. The main way to bring Vibrio into an uninfected herd is to buy sheep that are infected. Carrier sheep carry the bacteria in their intestinal tract for up to 18 months. Prevention practices for Vibrio include vaccination and not bringing new sheep into the herd.
Chlamydia psittaci, or Enzootic Abortion, causes abortions later than 90 days gestation. This is a zoonotic disease, which means humans can also be infected with it. This disease spreads through the air. Ways to prevent enzootic abortion include feeding Aureomycin (200 mg/hd/day) the last 6 weeks of pregnancy and vaccinating 30 days prebreeding with a booster 60 days later.
Enterotoxemia, or overeating disease occurs when lambs eat too much grain. Grains contain carbohydrates, which ferment and allow the growth of the bacteria Clostridium perfringens in the small intestine. This bacteria grows quickly in the gut and produces toxins. The toxins can cause sudden death. Vaccination is very beneficial in prevention of overeating disease. All feeder lambs should be vaccinated twice for Clostridium perfringens Type C and D. All ewes and rams should also be vaccinated with Clostridium perfringens Type C and D once per year. This ideally would be given prelambing to develop colostral protection in the lambs.
Parasites are a major concern in sheep herds. Coccidia is a parasite which causes diarrhea, decreased gain and ill thrift in lambs. Lambs acquire coccidia by eating oocysts that are in the environment. The oocysts are ingested by the lamb, then it takes 2-4 weeks for the coccidia to develop in the intestines, then more coccidian are shed in the manure into the environment. Coccidia flourish in wet pastures or feedlots and stressed sheep are more susceptible. Coccidia can be prevented by putting Bovatec or Deccox in the feed.
Other problem parasites in sheep are worms. There are several common worms that can infect sheep. Worms are a common cause of decreased gain, ill thrift and can even cause death. Deworming protocols should include rotating dewormers on an annual basis. There are many dewormers are the market. Several rules of thumb to ensure you are rotating are that all white drenches are in the same drug family, rotate between a white drench and ivomec and Levasole is another family, but worms seem to be more resistant to this drug. Check fecal samples 1-2 weeks after deworming to check efficacy.