Ivermectin: controlled test of anthelmintic activity in dairy calves with emphasis on Dictyocaulus viviparus.
Twelve dairy calves, naturally infected with lungworms and gastrointestinal parasites, were selected for a controlled test with single doses of ivermectin, administered subcutaneously, at the dose rate of 200 micrograms/kg. Specific interest was on efficacy of ivermectin against lungworms (Dictyocaulus viviparus), with ancillary interest directed on abomasal parasites. Ivermectin was administered to 6 calves, and the vehicle only, to 6 calves. At necropsy, 7 days after treatment, lungworms were not recovered from any of the treated calves; nontreated calves, given the vehicle only, were infected with 1 to 46 lungworms each. Removal efficacy against adult Ostertagia ostertagi was 99%. Fourth-stage Ostertagia spp and Trichostrongylus spp and mature Trichostrongylus axei, present in low numbers, were all removed. The fecal egg count for gastrointestinal parasites indicated all eggs, except for a few Nematodirus eggs, were cleared from treated calves. One treated calf showed signs of irritation of the neck at injection site for a short time after treatment and 1 treated calf had a slight indurated area at injection site at necropsy.
D000018:Abomasum / Q000469:parasitology; D000818:Animals; D000871:Anthelmintics / Q000627:therapeutic use*; D002417:Cattle; D002418:Cattle Diseases / Q000188:drug therapy*; D002986:Clinical Trials as Topic / Q000662:veterinary; D004021:Dictyocaulus / Q000187:drug effects*; D004022:Dictyocaulus Infections / Q000188:drug therapy*; D005243:Feces / Q000469:parasitology; D005260:Female; D007411:Intestinal Diseases, Parasitic / Q000188:drug therapy / Q000662:veterinary*; D007559:Ivermectin; D007783:Lactones / Q000627:therapeutic use*; D008297:Male; D008681:Metastrongyloidea / Q000187:drug effects*; D009349:Nematode Infections / Q000188:drug therapy / Q000662:veterinary*
D000871:Anthelmintics; D007783:Lactones; D007559:Ivermectin