title: Activity of ivermectin against canine intestinal helminths.
abstract: The anthelmintic activity of ivermectin was tested in 98 dogs against adult ascarids (Toxocara canis, Toxascaris leonina), hookworms (Ancylostoma caninum, A braziliense), and whipworms (Trichuris vulpis), and against experimentally induced infections (4th-stage larvae) of T canis and A caninum. Dosage levels tested were single subcutaneous injections of 50, 100, 200, or 400 micrograms/kg of body weight with appropriate vehicle-treated controls. A minimum of 4 (usually 5) dogs were tested with each parasite and dosage level. The lowest dosage level, 50 micrograms/kg, and all higher dosage levels expelled greater than 99% of the adult forms of both species of hookworms and intestinal larval forms of A caninum, as determined by worm counts at necropsy. A dosage level of 100 micrograms/kg was required to expel greater than 99% of whipworms and 200 micrograms/kg was necessary to expel adult (91%) and larval (97%) stages of T canis. Ivermectin was only marginally effective (34.2%, 46.2%, 69.2%, and 53.8%) against Toxascaris leonina at 50, 100, 200, and 400 micrograms/kg, respectively, and had no effect against occasional infections with the tapeworms, Dipylidium caninum (14 dogs) and Taenia spp (3 dogs).
mesh_terms: D000724:Ancylostomiasis / Q000188:drug therapy / Q000662:veterinary; D000818:Animals; D000871:Anthelmintics / Q000008:administration & dosage / Q000627:therapeutic use*; D004283:Dog Diseases / Q000188:drug therapy*; D004285:Dogs; D005260:Female; D006373:Helminthiasis / Q000188:drug therapy; D006374:Helminthiasis, Animal; D007411:Intestinal Diseases, Parasitic / Q000188:drug therapy / Q000662:veterinary*; D007559:Ivermectin; D007783:Lactones / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male; D014120:Toxocariasis / Q000188:drug therapy / Q000662:veterinary; D014257:Trichuriasis / Q000188:drug therapy / Q000662:veterinary
chemical_list: D000871:Anthelmintics; D007783:Lactones; D007559:Ivermectin