A questionnaire study on parasite control practices on UK breeding Thoroughbred studs.
Authors: Relf V E, Morgan E R, Hodgkinson J E, Matthews J B
Journal: Equine veterinary journal
Summary
# Parasite Control Practices on UK Thoroughbred Studs: A Gap Between Awareness and Action Anthelmintic resistance in equine parasites represents a genuine threat to stud health, yet a 2012 questionnaire survey of 61 UK Thoroughbred breeding establishments revealed a stark disconnect between owners' stated concerns about resistance and their actual management practices. The researchers documented that whilst most respondents expressed worry about resistance development, over half co-grazed visiting animals with permanent stock without pre-arrival treatment in 74% of cases, and indiscriminate whole-group macrocyclic lactone dosing—a significant driver of resistance—was commonplace, with movement to 'clean grazing' post-treatment reported by more than a quarter of studs. Faecal egg count (FEC) testing, a cornerstone of targeted parasite control, had been used by few establishments, and only 22% viewed it as useful for informing treatment decisions, suggesting fundamental misunderstanding of diagnostic utility. The findings expose a critical knowledge gap: many stud managers remain unaware of evidence-based resistance risk factors and continue blanket-treatment protocols despite their documented contribution to anthelmintic failure. For practitioners advising breeding operations, this underscores the urgent need for veterinary-led education around selective dosing, strategic use of FEC analysis, and risk-based protocols—moving the industry from reactive, indiscriminate treatment towards genuinely sustainable parasite management that preserves drug efficacy for future generations.
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Practical Takeaways
- •Review your quarantine and treatment protocols for introduced horses—co-grazing without pre-treatment anthelmintics significantly increases resistance risk
- •Stop treating all animals indiscriminately; use faecal egg count testing to identify which individuals actually need treatment and target your anthelmintic use accordingly
- •Work with your veterinarian to develop a targeted parasite control strategy based on diagnostic testing rather than routine whole-group treatments, which accelerates resistance development
Key Findings
- •56% of UK Thoroughbred studs co-grazed visiting horses with permanent stock despite anthelmintic resistance concerns, with <74% administering anthelmintics prior to integration
- •Most respondents administered frequent macrocyclic lactone treatments with no animals left untreated in any group administration, indicating indiscriminate whole-group treatment practices
- •>25% of studs reported moving animals to 'clean grazing' after treatment, demonstrating lack of awareness about anthelmintic resistance risk factors
- •Only 22% of studs considered faecal egg count analysis beneficial for determining anthelmintic choice, and few had conducted such analysis in the preceding year