Summary

Modern horse parasite control is an emphasis on strategic deworming rather than routine rotational treatments. Traditional deworming every six weeks has led to widespread parasite resistance, particularly in small strongyles. Research shows that a small percentage of horses contribute most of the pasture contamination, so individualized care is essential. The recommended approach includes performing fecal egg counts (FECs) to classify horses as low, medium, or high shedders and tailoring deworming frequency accordingly. Fecal egg reduction count tests help identify drug resistance and select effective medications. Seasonal factors are important, as deworming may not be necessary during hot summer months when parasite eggs are inactive. Strategic deworming reduces drug overuse, slows resistance, improves horse health, and supports better farm management overall.