Efficacy of clorsulon for treatment of mature naturally acquired and 8-week-old experimentally induced Fasciola hepatica infections in cattle.
In a dose-titration study against experimentally induced 8-week-old Fasciola hepatica infection (study A), 20 calves were allotted to 5 groups, each of 4 calves, and treated with different doses of an injectable formulation of clorsulon or its vehicle: group 1--controls, no drug; group 2--2 mg of clorsulon /kg; group 3--4 mg of drug/kg; group 4--8 mg/kg; and group 5--16 mg/kg. Mean numbers of flukes recovered from 4 calves in each treatment group were as follows: group 1--112.2, group 2--42, group 3--4.8, group 4--3.0, and group 5--0.2. Percentages of fluke reductions for groups 2, 3, 4, and 5 ( clorsulon -treated) calves were 62.6%, 95.7%, 97.3%, and 99.8%, respectively. Against naturally acquired mature (greater than 14-week-old) F hepatica infections (study B), a total of 161 flukes were recovered from 7 vehicle-treated control calves (group 6; mean fluke recovery = 23) and no flukes were recovered from 9 calves (group 7) given orally a formulation containing 7 mg of clorsulon /kg of body weight. Eggs were not found in the feces of clorsulon -treated calves at 20 to 21 days after treatment as compared with a mean of 7.4 eggs per gram (epg) in group 6 (control) calves. Mean bile egg recoveries were 13,532 (456 to 66,861) from group 6 calves as compared to recovery of a total of 162 (0 to 160) eggs from 3 of the 9 treated calves.(ABSTRACT TRUNCATED AT 250 WORDS)
D000818:Animals; D000980:Antiplatyhelmintic Agents / Q000008:administration & dosage* / Q000494:pharmacology / Q000627:therapeutic use; D002417:Cattle; D002418:Cattle Diseases / Q000188:drug therapy* / Q000469:parasitology; D005210:Fasciola hepatica / Q000187:drug effects; D005211:Fascioliasis / Q000188:drug therapy / Q000469:parasitology / Q000662:veterinary*; D005243:Feces / Q000469:parasitology; D005260:Female; D008297:Male; D010270:Parasite Egg Count / Q000662:veterinary; D013424:Sulfanilamides / Q000008:administration & dosage* / Q000494:pharmacology / Q000627:therapeutic use
D000980:Antiplatyhelmintic Agents; D013424:Sulfanilamides; C015675:clorsulon