Evaluation of Three Water-Suspensible Formulations of Fenbendazole against Ascaridia galli Infection in Broiler Chickens

Three formulations of water-suspensible fenbendazole, at target doses of 30.3 or 60.6 ppm in the drinking water, were administered to broilers infected with Ascaridia galli. The medication was administered in the water through automatic medicators for 6 hours on 3 consecutive days. Three days after treatment, chickens were killed and their worms were counted. Efficacy of fenbendazole was 99.2-100% and 69.0-89.6% at administration doses of 60.6 ppm and 30.3 ppm, respectively. Worm burden and percentage of broilers infected were lower in treated broilers than in controls (P < or = 0.05). Formulation A was dispensed most consistently and in the highest concentration through automatic medicators into the drinking water.