Effects of intermittent and continuous administration of decoquinate on bovine coccidiosis in male calves.
Male Holstein calves were each inoculated with 350,000 sporulated oocysts of Eimeria bovis. Two calves were given decoquinate (0.5 mg/kg of body weight) continuously in dry feed for 29 days, and 2 calves each were given 0.5, 1, or 1.5 mg of decoquinate/kg on an every 2nd-or 3rd-day schedule for 29 days. Calves given decoquinate continuously did not discharge oocysts but had slightly loose feces. In general, the number of oocysts discharged increased and fecal consistency decreased as the time between feeding of medicated feed increased. Calves given 0.5 or 1.5 mg of decoquinate/kg every 3rd day discharged more oocysts and had more diarrhea than did calves given 1 mg of decoquinate/kg every 3rd day. At postinoculation day 29, calves were euthanatized. At necropsy, intestinal tissues of calves given decoquinate were mostly normal. Apparently, reduced infections along with the elapsed time were sufficient to resolve most intestinal lesions caused by the coccidia. Decoquinate was most effective when fed continuously at 0.5 mg/kg. However, when fed at 1 or 1.5 mg of decoquinate/kg every 2nd day or 1.5 mg of decoquinate/kg every 3rd day, oocyst production was reduced and clinical coccidiosis was prevented.
Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Illinois, Urbana 61801.
P R
PR
Fitzgerald
M E
ME
Mansfield
D000284:Administration, Oral; D000821:Animal Feed; D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000188:drug therapy* / Q000469:parasitology; D003048:Coccidiosis / Q000188:drug therapy / Q000469:parasitology / Q000662:veterinary*; D003667:Decoquinate / Q000008:administration & dosage* / Q000627:therapeutic use; D004334:Drug Administration Schedule / Q000662:veterinary; D004539:Eimeria / Q000187:drug effects; D005243:Feces / Q000469:parasitology; D006912:Hydroxyquinolines / Q000008:administration & dosage*; D007814:Larva / Q000187:drug effects; D008297:Male; D013997:Time Factors
D006912:Hydroxyquinolines; D003667:Decoquinate