Necrotic colitis in two cats - a description of the lesions.

The lesions in two cases of necrotic colitis in old cats are described. Both had gross lesions of a necrotic, hemorrhagic colitis without gross lesions in the small intestine. Histologically the lesions resembled those of feline panleukopenia virus infection, namely: necrosis and loss of crypt epithelium, dilation of crypts and lining of crypts by flattened epithelium, subsequent collapse of the lamina propria and hemorrhage from subepithelial capillaries. Both grossly and histologically these lesions were restricted to the colon without similar involvement of the small intestine.The histories and clinical signs, the virological and hematological studies suggest that feline panleukopenia virus was not the etiological agent in these cases. No other causal agent was identified.