Anthelmintic activity of oxfendazole in pigs.

Eighty-five pigs were artificially infected with Hyostrongylus rubidus, Oesophagostomum species and Ascaris suum. On days 2, 10, 20 or 51 after infection groups of six were treated with oxfendazole premix in food at various dose rates. Subsequently the pigs were slaughtered for comparative worm counts to be made in treated and control animals. The efficacy of treatment against hyostrongylus worms of increasing age was 68, 57, 99.8 and 100 per cent after a 3 mg per kg dose, 75, 75, 99.8 and 100 per cent after a 4.5 mg per kg dose and 81, 83, 99.8 and 100 per cent after a 6 mg per kg dose. In the case of Oesophagostomum species the corresponding figures were 78, 100, 100 and 100 per cent efficacy after a 3 mg dose, 93, 100, 100 and 100 per cent after a 4.5 mg per kg dose and 91, 99, 100 and 100 per cent after a 6 mg per kg dose. Ascaris infestation established too poorly for significant results to be obtained. It is concluded that a dose rate of 4.5 mg oxfendazole per kg body-weight should give practical control of Hyostrongylus and Oesophagostomum species in pigs.