Anthelmintic effect of nitarsone on Ascaridia dissimilis infections in the turkey

Abstract

Turkey poults were obtained at 1 d of age and placed in clean brooder pens. Subsequently, the following experimental groups of birds were established: 1) birds left as uninfected controls; 2) birds artificially infected on a weekly basis with standardized doses of Ascaridia dissimilis; or 3) birds artificially infected 3 times per week (trickle infections) with standardized doses of A. dissimilis. On a per-pen basis (23 birds per pen), birds on the weekly and trickle infection regimens were also given nitarsone-medicated feed on a continuous basis before and during the infection process (prophylactic treatment) or were given the nitarsone feed after all infective eggs were administered (therapeutic treatment). All medicated feeds were mixed to contain nitarsone at 0.01875%. No differences in FE or bird growth were shown to develop because of bird diet or infection status. Neither regimen of nitarsone medication resulted in significantly decreased worm burdens. The production of eggs by A. dissimilis females, however, was affected greatly by inclusion of nitarsone in the diet. Egg production by ascarids was completely restricted in turkeys that received the prophylactic treatment of nitarsone, and egg production by ascarids was decreased by 97% in turkeys that received the therapeutic treatment compared with the nonmedicated birds. Additionally, dietary nitarsone was shown to stunt adult ascarid length significantly.