Clostridium perfringens produces enteric diseases, generically called enterotoxemias, in sheep, goats, and other animals. This microorganism can be a normal inhabitant of the intestine of most animal species, including humans, but when the intestinal environment is altered by sudden changes in diet or other factors, C. perfringens proliferates and produces potent toxins that act locally or are absorbed into the general circulation with usually devastating effects on the host. History, clinical signs, and gross postmortem findings are useful tools for establishing a presumptive diagnosis of clostridial enterotoxemia in sheep and goats. Definitive diagnosis requires laboratory confirmation. Isolation of some types of C. perfringens (e.g., B and C) can be of diagnostic value, but other types (e.g., A) are so commonly found in the intestine of normal animals that isolation is meaningless from a diagnostic point of view. The most accepted criterion in establishing a definitive diagnosis of enterotoxemia is detection of C. perfringens toxins in intestinal contents. Also, histopathological examination of brain is very useful for diagnosis of type D disease, as lesions produced by epsilon toxin in the brains of sheep and goats are pathognomonic for type D enterotoxemia. Ancillary tests, such as measuring urine glucose or observing Gram-stained smears of intestinal mucosa, can be used. However, although such tests have a presumptive diagnostic value when positive, they cannot be used to rule out a diagnosis of enterotoxemia when negative.