Disease associated with type A strains of Clostridium perfringensis a milder condition than disease associated with C perfringens type C. Diagnosis is challenging, because C perfringens type A is part of the normal intestinal microbiota, microscopic lesions are not consistent, and disease has not been consistently reproduced experimentally.
Affected piglets typically have a creamy to watery, yellowish diarrhea that is self-limiting within approximately 5 days. Piglets' growth rates are suppressed; however, few pigs die. Lesions at postmortem examination are mild and generally nonspecific; they include flaccid, thin-walled intestines with variable gas distention. No specific criteria are available to confirm a diagnosis of C perfringens enteritis in swine, given the microorganism's ubiquity in the microbiota. Diagnosis is often by exclusion of other causes of neonatal diarrhea and by isolation and identification of large numbers of C perfringens from affected segments of jejunum or ileum.
