Susceptibility of fourth-stage Ascaris suum larvae to fenbendazole and to host response in the pig.
Fenbendazole given at the rate of 2.5 g/kg of feed for 3 days had 100% efficacy against 4th-stage Ascaris suum larvae in 8 pigs. Eight control pigs had a total of 108 A suum. In 6 pigs infected 3 times with 3rd-stage A suum larvae and treated with fenbendazole after the larvae molted to the 4th stage, the challenge exposure-derived population was decreased by 64%. Similar sequential infections in 6 pigs similarly infected, but not treated with fenbendazole, decreased the challenge exposure-derived population by 98%; however, developing and/or adult worms from the vaccinating infections were present.
D000818:Animals; D001196:Ascariasis / Q000188:drug therapy / Q000276:immunology / Q000662:veterinary*; D001200:Ascaris / Q000187:drug effects*; D001562:Benzimidazoles / Q000627:therapeutic use*; D005260:Female; D005273:Fenbendazole / Q000494:pharmacology / Q000627:therapeutic use*; D007113:Immunity, Innate; D007814:Larva / Q000187:drug effects; D008297:Male; D013552:Swine; D013553:Swine Diseases / Q000188:drug therapy*
D001562:Benzimidazoles; D005273:Fenbendazole