Parasitic infections can modify the host’s ability to metabolize drugs by altering the biotransformation enzymes.
Mouflon (Ovis musimon), the wild sheep, is very sensitive to parasitic diseases. In the present study, in vitro activities
of thirteen hepatic biotransformation enzymes and the in vitro metabolism of albendazole and flubendazole were
compared in old mouflon ewes, either non-infected or infected with lancet flukes (Dicrocoelium dendriticum). The most
pronounced decline in 6β-testosteron hydroxylase, glutathione-S-transferase and UDP-glucuronosyl transferase activities
was observed in Dicrocoelium-infected animals. In addition, dicrocoeliosis caused a decrease in both albendazole and
flubendazole phase I hepatic metabolism. However, the changes were very slight therefore any undesirable alterations in
albendazole and flubendazole pharmacokinetics are not expected. Decreased activities of 66β-testosterone hydroxylase,
glutathione-S-transferase and UDP-glucuronosyl transferase can impair drug elimination from the infected animals. This
should be taken into consideration in pharmacotherapy or pharmacoprophylaxis of mouflons and sheep.