Efficacy of thiophanate and albendazole against natural infections of Dicrocoelium dentriticum, Fasciola hepatica, and gastrointestinal nematodes and cestodes in sheep.

The anthelmintic efficacy of thiophanate and albendazole was compared in sheep with heavy infestations of Dicrocoelium dentriticum. The effectiveness of each drug was determined by counting the numbers of D. dentriticum in animals killed 21 days after treatment. In one group, the dose of thiophanate recommended for use against gastrointestinal (GI) nematodes (50 mg kg-1 live weight) was found to be 74.4% effective against D. dentriticum. Two tablets (each containing 76 mg of active ingredient) of albendazole per 30 kg live weight were given to a second group and the dose repeated after 1 week. Under this regime, albendazole was found to be 12.7% effective against D. dentriticum. The effect of each drug on other parasites was as follows; thiophanate had no effect against Fasciola hepatica or cestodes, while albendazole was 71.5% effective against F. hepatica and 100% effective against cestodes. Both drugs were highly effective against GI nematodes.