In:
Journal of the American Veterinary Medical Association, American Veterinary Medical Association (AVMA), Vol. 225, No. 6 ( 2004-09-01), p. 903-910
Abstract:
Objective —To determine prevalence of anthelmintic
resistance in cyathostome nematodes of horses in the southern United States. Design —Cross-sectional study. Animals —786 horses on 44 farms and stables in
Georgia, South Carolina, Florida, Kentucky, and Louisiana. Procedure —Fecal egg count (FEC) reduction tests
were performed on 44 large farms and stables. Horses on each farm were treated with an oral paste formulation
of fenbendazole, oxibendazole, pyrantel pamoate, or ivermectin at recommended label dosages. A mixed
linear model was fitted to the percentage reduction in FEC, accounting for differences among farms, states,
ages, treatments, and treatment by state interactions. Results —By use of a conservative measure of resistance
( 〈 80% reduction), the percentage of farms with
anthelmintic-resistant cyathostomes was 97.7%, 0%, 53.5%, and 40.5% for fenbendazole, ivermectin, oxibendazole,
and pyrantel pamoate, respectively. Mean percentage reductions in FEC for all farms were 24.8%,
99.9%, 73.8%, and 78.6% for fenbendazole, ivermectin, oxibendazole, and pyrantel pamoate, respectively.
Pairwise contrasts between states for each treatment revealed that in almost all instances, there were no significant
differences in results between states. Conclusions and Clinical Relevance —The prevalence
of resistance found in this study was higher than that reported previously, suggesting that anthelmintic resistance
in equine cyathostomes is becoming a major problem. Furthermore, data from these 5 southern states,
which are geographically and physiographically distinct, were remarkably similar. This suggests that drug resistance
in cyathostomes is highly prevalent throughout the entire southern United States and probably nationwide.
( J Am Vet Med Assoc 2004;225:903–910)
Type of Medium:
Online Resource
ISSN:
0003-1488
DOI:
10.2460/javma.2004.225.903
Language:
Unknown
Publisher:
American Veterinary Medical Association (AVMA)
Publication Date:
2004
detail.hit.zdb_id:
2904887-4
SSG:
22
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