Observations on pigeon circovirus infection in Ontario.

Subclinical pigeon circovirus infection was diagnosed in 1-day-old to 6-week-old birds from a loft with no history of clinical disease. Pigeons from other lofts presented with various illnesses and were found at necropsy to be concurrently infected with pigeon circovirus.

The enteritis complex in domestic rabbits: A field study.

A study of the causative agents of enteritis in domestic rabbits from 44 different accessions is described. In descending order of frequency, the organisms most commonly demonstrated were intestinal and hepatic coccidia (Eimeria species), Escherichia coli, Clostridium spp., Salmonella, Bacillus piliformis, and rotavirus. The species of Eimeria identified included those moderately pathogenic and coccidia of low pathogenicity. Using seven antisera against known enterpathogenic strains of E. coli, only one strain, O15, was identified in three cases. Clostridium perfringens or C. spiroforme was demonstrated in the intestinal contents in 11 cases, and lesions compatible with clostridial enteropathy were identified on gross and histopathology. In a serological survey, over 50% of 200 fryer rabbits submitted to Ontario abattoirs and of animals from commercial rabbitries had detectable antibody to rotavirus, indicating the widespread distribution of rotaviral infections in this species. In the cases of enteritis studied, two or more potentially pathogenic organisms were frequently identified, emphasizing that several different organisms may be acting in concert to produce clinical disease.

Lincomycin-induced severe colitis in ponies: association with Clostridium cadaveris.

Four groups of two ponies, free of fecal Salmonella and Clostridium cadaveris, were treated as follows: Group A, control group; B, single nasogastrically administered dose of lincomycin (25 mg/kg) followed 48 h later by 3 L of C. cadaveris (10(9) organisms/mL); C, the same dose of lincomycin as group B; D, the same dose of C. cadaveris as group B on each of three occasions at 12 h intervals. Groups A and D remained healthy, but groups B and C developed severe colitis 48-56 h (B) or 72 h (C) after administration of lincomycin. Three ponies were euthanized and one in group B died. Clostridium cadaveris was isolated at about 10(6)/mL of colonic contents from these ponies, but one pony in group B also yielded Salmonella typhimurium from the colon. Subsequent challenge of group A ponies (3 L of C. cadaveris 10(9)/mL, three times at 12 h intervals) did not produce colitis. Nasogastric administration of lincomycin (25 mg/kg) to group A and D ponies, 20 days after administration of C. cadaveris, resulted in severe colitis in all ponies within 48-72 h. Salmonella agona was isolated from the colonic contents of one pony and C. cadaveris (10(6)/mL) from all four ponies. Clostridium cadaveris was not isolated from the colonic content of 45 healthy horses examined immediately after death. These studies confirm the potential for lincomycin to induce severe enterocolitis in ponies and implicate C. cadaveris further as a cause of "idiopathic colitis" in ponies.