Use of oxibendazole for control of cambendazole-resistant small strongyles in a band of ponies: a six-year study.

Abstract

Oxibendazole (OBZ; 10 mg/kg of body weight) was administered to ponies at 8-week intervals to control strongylosis in a breeding band of Shetland-type ponies (n = 29 to 50) from October 1978 through September 1984. A similar use of cambendazole (CBZ; 20 mg/kg of body weight) in this band of ponies during the preceding 4-year period resulted in the survival of a CBZ-resistant population (S) of small strongyles. Effectiveness of OBZ treatments was monitored by pre- and posttreatment counts of the number of strongyle eggs per gram of feces (epg) and of the number of strongyle larvae per gram of feces (lpg). For the first 4 years of the 6-year period, epg and lpg counts were determined for 3 to 5 of the OBZ treatments; during the last 2 years, counts were determined for each treatment. For the 1st year, the mean reduction in epg was 96%. During the 2nd and 3rd years, mean reductions in epg were 80% and 81%, respectively. For the 4th and 5th years, mean reductions in epg were 69% and 43%, respectively. For the 6th year, the mean reduction in epg was 37%. Statistical analyses of the epg data, using the linear plateau method, indicated a significant increase in residual (surviving) strongyle infections after the periodic OBZ treatments, with a mean annual increase in survival of 10.3% for the 6 years. Changes in lpg were variable, but an overall loss of effectiveness of the OBZ treatments was evident. Only infective larvae of small strongyles were observed in the cultures; larvae of 2 species of large strongyles, Strongylus vulgaris and Strongylus edentatus, were conspicuously absent.(ABSTRACT TRUNCATED AT 250 WORDS)

• Authors: J H Drudge, E T Lyons, S C Tolliver, T W Swerczek
• Journal: American journal of veterinary research (Am J Vet Res) Vol. 46 Issue 12 Pg. 2507-11 (Dec 1985) ISSN: 0002-9645 [Print] United States
• PMID: 4083584 (Publication Type: Journal Article)

Chemical References

• Benzimidazoles
• oxibendazole
• Cambendazole

Topics

• Animals
• Benzimidazoles (therapeutic use)
• Cambendazole (therapeutic use)
• Drug Resistance
• Female
• Horses
• Male
• Parasite Egg Count
• Strongyle Infections, Equine (drug therapy, parasitology)
• Strongyloidea (drug effects)
• Time Factors