Enterotoxemia in sheep and lambs
Enterotoxemia is a frequently severe disease of small ruminants of all ages. It is caused by two strains of bacteria called Clostridium perfringens, type C and D. Type C principally produces the β-toxin, which most commonly kills lambs less than 2 weeks of age. A typical symptom of lambs that die from β-toxin is simply sudden death. Type D principally produces the ε-toxin which affects lambs older than 2 weeks of age, particularly those eating diets high in starch. Lambs exposed to high doses of ε-toxin also die very quickly. Fatalities occur particularly in non-vaccinated animals or in newborn lambs whose mother was not vaccinated.
Vaccination of ewes 3-4 weeks before lambing improves passive protection in lambs up to 12 weeks of age, whereas there is no benefit of vaccinating lambs before 6 weeks of age. Since the causative bacteria proliferate in the intestine in response to ingestion of abnormally high levels of starch, sugar, or protein, there are two alternatives:
- to divide the daily allotment into as many small feedings as is feasible, or
- to feed roughages such as hay before feeding these higher-risk feeds.
These good practices, vaccination and Smart feeding strategies, can prevent animal losses and improve their welfare. Prevention of enterotoxemia is far more likely to be successful than trying to treat the disease. Treatment of enterotoxemia may not be successful in severe cases.