Efficacy of levamisole against abomasal nematodes and lungworms in dairy calves: preliminary tests indicating reduced activity for Ostertagia ostertagi.
Dairy calves (n = 18) were used in controlled tests to evaluate activity of levamisole against abomasal nematodes and lungworms. Two formulations of levamisole, injectable (experiment A) and bolus (experiment B), were given in single doses at rates of 6 mg/kg of body weight and 5.4 to 10.2 mg/kg (5.4, 7.6, 8.0, 8.8, or 10.2 mg/kg), respectively. Experiment A included 4 treated and 4 nontreated calves and experiment B consisted of 5 treated and 5 nontreated calves. Aggregate removals of Ostertagia spp (4th stage), Ostertagi (adult), Trichostrongylus spp (4th stage), and T axei (adult) were 0%, 54%, 86%, and 95%, respectively, for injectable treated calves and were 0%, 23%, no data, and 85%, respectively, for bolus-treated calves. Haemonchus spp, present in small numbers, were completely removed from treated calves in experiment A. Several possible explanations are discussed regarding poor removal activity of levamisole by both formulations against O ostertagi. Removal activity was 95% and 100% against Dictyocaulus viviparus for injectable-treated and bolus-treated calves, respectively.
D000018:Abomasum / Q000469:parasitology*; D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000188:drug therapy*; D004021:Dictyocaulus / Q000187:drug effects; D007978:Levamisole / Q000627:therapeutic use*; D008297:Male; D009349:Nematode Infections / Q000188:drug therapy / Q000662:veterinary*; D010029:Ostertagiasis / Q000469:parasitology; D014251:Trichostrongyloidea / Q000187:drug effects*
D007978:Levamisole