Efficacy of fenbendazole against five genera of swine parasites

Thirty-three pigs were sequentially infected with Oesophagostomum spp, Metastrongylus spp, and Trichuris suis while being maintained in lots contaminated with space Ascaris suum, Strongyloides ransomi, and other parasites. Pigs were assigned to 1 of 3 groups on the basis of weight (6.8 to 25.9 kg), sex, and litter. Pigs in the 1st group were used as nontreated controls; pigs in the 2nd and 3rd groups were given fenbendazole in the feed at doses of 3 and 5 mg/kg of body weight, respectively, on 3 successive days. Pigs were necropsied either on the 4th of 5th day after completion of treatment, and worms were recovered and counted. Based on the mean numbers of worms in the control group, drug efficacies at 3 and 5 mg/kg were, respectively, 100% against A suum; 59% and 81% against S ransomi; 97% and 99.9% against Metastrongylus spp; 94% and 99.7% against T suis; and 99.9% against Oesophagostomum spp.