Enterotoxemia Caused by Clostridium perfringens Types B and C

Infection with Clostridium perfringens types B and C causes severe enteritis, dysentery, toxemia, and high mortality in young lambs, calves, pigs, and foals. Types B and C both produce the highly necrotizing and lethal β toxin that is responsible for severe intestinal damage. This toxin is sensitive to proteolytic enzymes, and disease is associated with inhibition of proteolysis in the intestine. Sow colostrum, which contains a trypsin inhibitor, has been suggested as a factor in the susceptibility of young piglets. Type C also causes enterotoxemia in adult cattle, sheep, and goats. The diseases are listed below, categorized as to cause and host. C perfringens also has been associated with hemorrhagic enteritis in dogs. (See also intestinal diseases in horses, Intestinal Diseases in Horses and Foals: Introduction.)

Lamb dysentery: type B in lambs up to 3 wk of age. Calf enterotoxemia: types B and C in well-fed calves up to 1 mo. Pig enterotoxemia : type C in piglets during the first few days of life. Foal enterotoxemia: type B in foals in the first week of life. Struck: type C in adult sheep. Goat enterotoxemia : type C in adult goats.

Clinical Findings:

Lamb dysentery is an acute disease of lambs <3 wk old. Many may die before signs are seen, but some newborn lambs stop nursing, become listless, and remain recumbent. A fetid, blood-tinged diarrhea is common, and death usually occurs within a few days.

In calves, there is acute diarrhea, dysentery, abdominal pain, convulsions, and opisthotonos. Death may occur in a few hours, but less severe cases survive for a few days, and recovery over a period of several days is possible. Pigs become acutely ill within a few days of birth and there is diarrhea, dysentery, reddening of the anus, and a high fatality rate; most affected piglets die within 12 hr. In foals, there is acute dysentery, toxemia, and rapid death. Struck in adult sheep is characterized by death without premonitory signs.

Lesions:

Hemorrhagic enteritis with ulceration of the mucosa is the major lesion in all species. Grossly, the affected portion of the intestine is deep blue-purple and appears at first glance to be an infarction associated with mesenteric torsion. Smears of intestinal contents can be examined for large numbers of gram-positive, rod-shaped bacteria, and filtrates made for detection of toxin and subsequent identification by neutralization with specific antiserum.

Control:

Treatment is usually ineffective because of the severity of the disease, but if available, specific hyperimmune serum is indicated, and oral administration of antibiotics may be helpful. The disease is best controlled by vaccination of the pregnant dam during the last third of pregnancy: initially, 2 vaccinations 1 mo apart, and annually thereafter. When outbreaks occur in newborn animals from unvaccinated dams, antiserum should be administered immediately after birth.