Preliminary Data from Six Years of Selective Anthelmintic Treatment on Five Horse Farms in France and Switzerland.
Authors: Roelfstra Liselore, Quartier Marion, Pfister Kurt
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary: Six-Year Field Trial of Selective Anthelmintic Treatment in European Horse Populations Rising anthelmintic resistance in cyathostomins—particularly against benzimidazoles, tetrahydropyrimidines, and increasingly macrocyclic lactones—demands practical alternatives to blanket deworming protocols. Roelfstra and colleagues evaluated selective (or targeted selective) anthelmintic treatment (SAT) across five farms in France and Switzerland over six years, collecting twice-yearly faecal samples from 93 equids and processing them via McMaster technique to determine which animals actually required treatment based on fecal egg count (FEC) thresholds. Of 757 total samples analysed, only 263 (34.7%) exceeded the 200 eggs per gram treatment threshold, meaning nearly two-thirds of routine sampling occasions required no anthelmintic intervention whatsoever. This substantial reduction in treatment frequency directly translates to decreased anthelmintic selection pressure on parasite populations, potentially preserving drug efficacy longer and reducing unnecessary chemical exposure in individual horses. For practitioners adopting SAT protocols, the data suggest that faecal egg counting—combined with clinically appropriate treatment thresholds—can substantially lower overall anthelmintic usage on well-managed farms whilst maintaining adequate parasite control, though individual farm management practices and animal health status will influence outcomes.
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Practical Takeaways
- •Fecal egg count monitoring allows you to treat only horses that actually need it, reducing unnecessary drug use and costs by approximately 65%
- •Implementing selective treatment protocols helps slow the development of anthelmintic resistance, which is increasingly problematic against benzimidazoles, tetrahydropyrimidines, and macrocyclic lactones
- •SAT is a practical field strategy that works across different farm settings—monitor individual horses twice yearly and treat only those exceeding 200 EpG threshold
Key Findings
- •Over six years across five farms, only 34.7% of 757 fecal samples (263 samples) had fecal egg counts ≥200 EpG requiring treatment
- •Selective anthelmintic treatment (SAT) demonstrates significant potential for reducing overall anthelmintic treatment frequency and drug pressure
- •SAT protocol can be successfully implemented in field conditions across multiple farms in France and Switzerland