Liver enzyme activity and histological changes in the liver of silver foxes (Vulpes vulpes fulva) experimentally infected with opisthorchiid liver flukes. A contribution to the pathogenesis of opisthorchiidosis

Blood samples from silver foxes experimentally infected with Opisthorchis felineus and Metorchis bilis, respectively, were examined for the activity of liver enzymes. The average activities of aspartate aminotransferase (AST), glutamate dehydrogenase (GLDH), alkaline phosphatase and alanine aminotransferase in uninfected control animals were 20, 1.8, 57 and 44 units/l, respectively. The liver enzymes in infected foxes reacted differently, depending on dose, species of flukes and individual peculiarities. The highest individual deviation of infected from control animals was registered in the case of GLDH, reaching increases of up to 200-fold. In contrast, AST showed the lowest deviation from control values (less than 10-fold). By the end of the study period, enzyme activities had declined. The prepatent periods for M. bilis and O. felineus in foxes were 2 weeks and 4 weeks, respectively. High egg per gram values were established at the beginning of the patent period. At necropsy, chronic inflammatory reactions were found in the bile ducts and in the wall of the gall bladder. The number of flukes at the end of the study was low