Toxigenic types of Clostridium perfringens are important causes of enteric disease in domestic animals, although type E is putatively rare, appearing as an uncommon cause of enterotoxemia of lambs, calves, and rabbits. We report here two geographically distinct cases of type E enterotoxemia in calves, and diagnostic findings which suggest that type E may play a significant role in enteritis of neonatal calves. The cases had many similarities, including a history of diarrhea and sudden death, abomasitis, and hemorrhagic enteritis. In both cases, anaerobic cultures of abomasum yielded heavy growth of C. perfringens genotype E. Four percent of > 1000 strains of C. perfringens from cases of enteritis in domestic animals were type E, and all (n=45) were from neonatal calves with hemorrhagic enteritis. Furthermore, type E isolates represented nearly 50% of all isolates submitted from similar clinical cases in calves. Commercial toxoids available in North America have no label claims for efficacy against type E infections. Consideration should be given to type E-associated enteritis when planning for the health care of calves.