Evaluation of Levamisole Against Experimental Infections of Ascaridia, Heterakis, and Capillaria spp. in Chickens

SUMMARY Three hundred Vantress/Arbor Acre cockerel and pullet chicks were experimentally inoculated with Ascaridia galli, with Capillaria obsignata, or with A. galli and Heterakis gallinarum. At 28 days after chicks were inoculated, they were treated with various dose levels of levamisole HCl given in ½ the amount of water previously consumed daily. Against A. galli infections, levamisole HCl at dose level of 18 mg./kg. of body weight was 98% effective. The effect of the dose of 12 mg./kg. was erratic; efficacy ranged from 35 to 83% in 40 chicks. Against H. gallinarum, 99% of the worms were removed from chicks created with levamisole HC1 at dose level of 36 mg./kg. of body weight; 86 to 92% of the worm burden was removed when chicks were treated at the dose level of 24 mg./kg. Capillaria obsignata was the most difficult of the 3 species to remove; a dose rate of 36 mg./kg. was required to obtain 95 to 99% anthelmintic effectiveness. A total of 120 Vantress/Arbor Acre cockerel and bullet chicks were experimentally inoculated with a mixed parasitic population (the 3 species). Twenty-eight days after chicks were inoculated, they were created with levamisole HCl (36 mg./kg. of body weight) given in ½ the daily consumption of drinking water. On the basis of numbers of worms recovered from the chicks at necropsy (4 and 5 days after treatement), levamisole HCl removed 100, 97, and 92% of A. galii, H. gallinarum, and C. obsignata, respectively. At the dose rates used, the drug was not unpalatable and did not produce signs of toxicosis.