Efficacy of fenbendazole for treatment of giardiasis in calves.

Abstract

OBJECTIVE:

To determine efficacy of fenbendazole for treatment of giardiasis in calves.

ANIMALS:

Twenty male and 15 female Holstein calves (100 to 180 kg), naturally infected with Giardia sp.

PROCEDURE:

In vitro fenbendazole susceptibility and resistance development was determined for a ruminant Giardia isolate by use of an adherence assay. Calves were treated as follows: group 1, a single administration of 5 mg of fenbendazole/kg of body weight; group 2, a single administration of 10 mg of fenbendazole/kg; group 3, 5 mg of fenbendazole/kg, every 24 hours for 3 days; group 4, 10 mg of fenbendazole/kg, every 24 hours for 3 days; group 5, 20 mg of fenbendazole/kg, every 24 hours for 3 days; group 6, 0.833 mg of fenbendazole/kg, every 24 hours for 6 days; and group 7, saline solution. Fecal Giardia cysts were counted on days -3 through -1 and 1 through 7, 9, 11, 13, 21, and 28 by use of sucrose gradient concentration and staining with a fluorescent monoclonal antibody.

RESULTS:

The 50% adherence inhibition concentration was 0.024 +/- 0.002 microgram/ml, and resistance could not be detected after 5 weeks of continuous culture at sublethal concentration of fenbendazole (0.01 microgram/kg). Fenbendazole was 100% effective in eliminating cysts from the feces within 6 days for calves in treatment groups 2-6. Reinfection was observed in some calves within the 28-day study period.

CONCLUSIONS:

Fenbendazole is effective in the elimination of Giardia infections in calves, but repeat treatments may be required in reinfected animals.

CLINICAL RELEVANCE:

Fenbendazole is an effective and economical treatment for Giardia-associated diarrhea and growth rate reduction in calves.

• Authors: R M O'Handley, M E Olson, T A McAllister, D W Morck, M Jelinski, G Royan, K J Cheng
• Journal: American journal of veterinary research (Am J Vet Res) Vol. 58 Issue 4 Pg. 384-8 (Apr 1997) ISSN: 0002-9645 [Print] United States
• PMID: 9099384 (Publication Type: Clinical Trial, Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)

Chemical References

• Antiprotozoal Agents
• Fenbendazole

Topics

• Animals
• Antiprotozoal Agents (pharmacology, standards, therapeutic use)
• Cattle
• Cattle Diseases (drug therapy, physiopathology, prevention & control)
• Dose-Response Relationship, Drug
• Feces (parasitology)
• Female
• Fenbendazole (pharmacology, standards, therapeutic use)
• Giardia (drug effects, isolation & purification)
• Giardiasis (drug therapy, prevention & control, veterinary)
• Male