Variations of plasma enzymes in the pony and the dog after carbon tetrachloride administration.

Adult female dogs or pony mares were subjected to a nonlethal dose of CCl4 (0.5 ml/kg of body weight). Amounts of several plasma enzymes thought to be indicative of hepatic disease were monitored. Plasma enzymes alanine aminotransferase, aspartate aminotransferase (AST), alkaline phosphatase (ALP), arginase, gamma-glutamyltransferase (GGT), and iditol dehydrogenase (ID), as well as total plasma bilirubin, were determined in these animals before and after the administration of the CCl4. In the dog, GGT was not significantly increased, whereas ALP values were increased during days 1 to 6. In the pony, GGT was significantly increased during the entire course of the study, whereas ALP exhibited only small, transient (though significant) increases. Responses of ID, AST, and ALP were unremarkable when compared between the pony and the dog. Total bilirubin was significantly (P less than or equal to 0.05) increased from days 1 to 4 (pony) or days 5 to 8 (dog) after the CCl4 dose, but subsequently returned to or decreased below base-line values. Animals did not have evidence of icterus at any time. Seemingly, the dog and the pony are distinct clinical entities, and only the appropriate laboratory tests for each species should be used to provide information for the clinicopathologic evaluation of hepatic disease.