Strongylus vulgaris associated with usage of selective therapy on Danish horse farms-is it reemerging?
Abstract: Nematodes belonging to the order Strongylida are ubiquitous in grazing horses, and the large strongyle Strongylus vulgaris is considered the most pathogenic. This parasite was originally described widely prevalent in equine establishments, but decades of frequent anthelmintic treatment appears to have reduced the prevalence dramatically. Increasing levels of anthelmintic resistance in cyathostomin parasites have led to implementation of selective therapy to reduce further development of resistance. It has been hypothesized that S. vulgaris could reoccur under these less intensive treatment circumstances. The aim with the present study was to evaluate the occurrence of S. vulgaris and the possible association with usage of selective therapy. A total of 42 horse farms in Denmark were evaluated for the presence of S. vulgaris using individual larval cultures. Farms were either using a selective therapy principle based on regular fecal egg counts from all horses, or they treated strategically without using fecal egg counts. A total of 662 horses were included in the study. Covariate information at the farm and horse level was collected using a questionnaire. The overall prevalence of S. vulgaris was 12.2% at the individual level and 64.3% at the farm level. Farms using selective therapy had horse and farm prevalences of 15.4% and 83.3%, respectively, while the corresponding results for farms not using selective therapy were 7.7% and 38.9%. These findings were found statistically significant at both the horse and the farm level. Stud farms using selective therapy were especially at risk, and occurrence of S. vulgaris was significantly associated with the most recent deworming occurring more than six months prior. The results suggest that a strict interpretation of the selective therapy regimen can be associated with an increased prevalence of S. vulgaris. This suggests that modifications of the parasite control programs could be considered on the studied farms, but it remains unknown to which extent this can be associated with increased health risks for infected horses.
Copyright © 2012 Elsevier B.V. All rights reserved.
Publication Date: 2012-05-09 PubMed ID: 22703964DOI: 10.1016/j.vetpar.2012.04.039Google Scholar: Lookup
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Summary
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The research paper investigates the occurrence of Strongylus vulgaris, a commonly found parasite in grazing horses, in relation to the use of selective therapy on Danish horse farms. It suggests that the prevalence of this parasite may be increasing due to less intensive treatments.
About Strongylus vulgaris
- Strongylus vulgaris is a large strongyle, and it’s deemed the most pathogenic among nematodes commonly present in grazing horses.
- Frequent anthelmintic treatments have considerably reduced this parasite’s prevalence over the last decades.
- However, there has been an increase in anthelmintic resistance in cyathostomin parasites leading to the setup of more selective treatments to prevent further resource of resistance.
Study Aim and Methodology
- The study aims to comprehend the frequency of S. vulgaris and its potential association with the use of selective therapy.
- To conduct the research, the study selected 42 horse farms in Denmark, which were then evaluated for the presence of Strongylus vulgaris.
- The farms surveyed were either using a selective therapy dictation based on regular fecal egg counts from horses or were treating strategically but not using fecal egg counts.
- In total, the study encompassed 662 horses. The team collected covariate data at the farm and horse levels using questionnaires.
Findings
- The overall prevalence of S. vulgaris was found to be 12.2% at the individual level and 64.3% at the farm level.
- An important discovery was that farms using selective therapy had higher horse and farm prevalences of 15.4% and 83.3%, respectively. The corresponding figures for farms not using selective therapy were significantly lower, being 7.7% (horse level) and 38.9% (farm level).
- These disparities were statistically significant at both the horse and farm level.
- The study also identified that stud farms utilizing selective therapy were especially at risk.
- The occurrence of S. vulgaris was considerably associated with the most recent deworming happening six months prior or more.
Implications and Considerations
- The study suggests that a rigid interpretation of the selective therapy regimen correlates with an increased prevalence of S. vulgaris.
- Therefore, it advises considering modifications to the parasite control programs on the farms studied.
- However, the extent to which these changes can be associated with increased health risks for infected horses remains uncertain.
Cite This Article
APA
Nielsen MK, Vidyashankar AN, Olsen SN, Monrad J, Thamsborg SM.
(2012).
Strongylus vulgaris associated with usage of selective therapy on Danish horse farms-is it reemerging?
Vet Parasitol, 189(2-4), 260-266.
https://doi.org/10.1016/j.vetpar.2012.04.039 Publication
Researcher Affiliations
- Department of Large Animal Sciences, Faculty of Life Sciences, University of Copenhagen, Denmark. martin.nielsen@uky.edu
MeSH Terms
- Animals
- Anthelmintics / therapeutic use
- Denmark / epidemiology
- Female
- Horse Diseases / drug therapy
- Horse Diseases / parasitology
- Horses
- Male
- Strongylida Infections / drug therapy
- Strongylida Infections / parasitology
- Strongylida Infections / veterinary
- Strongylus / drug effects
Citations
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