Efficacy of oxfendazole against Nematodirus battus and inhibited stages of sheep nematodes.

Oxfendazole administered at a dose rate of 5 mg/kg was 100 per cent effective against artificially acquired seven-day-old and 23-day-old infections of Nematodirus battus in lambs. At the same dose rate it was 100 per cent effective against naturally acquired infections of adult Trichostrongylus spp, adult and arrested early fourth stage larvae of Haemonchus contortus and Nematodirus spp. Efficacy against Ostertagia spp was 99 to 100 per cent against adults and 100 per cent against inhibited larvae, the predominant species of this genus being O circumcincta.