RESUMEN
Equine Anoplocephalosis constitute a significant problem in horses worldwide. The aim of this study was to analyse intrinsic (host age and sex) and extrinsic (management type, pasture type and moisture) factors that influence the prevalence and FEC of A. perfoliata infections. Faecal samples were collected from 994 horses managed in studs or individually between 2012 and 2014. The Sedimentation-flotation method was applied for coproscopic analysis, and faecal egg counts were calculated. The overall prevalence was 25.1% (21.4-29.0) with the highest prevalence (36.1% [28.1-44.8]) found in horses 10-20 years old. The individuals kept in studs showed three times higher A. perfoliata prevalence compared to the ones managed individually. The prevalence significantly differed between pasture types, with individuals kept in studs (37.6% [34.3-40.9]) showing four times higher prevalence than horses kept individually (9.2% [4.8-16.5]). More horses kept on watery (42.0% [36.6-47.6]) and semi-watery (35.9% [31.3-40.7]) pastures were infected than those on dry (6.6% [4.6-9.2]) pastures. The overall A. perfoliata FEC in all examined individual was 2.67 and differed within sex, with mares showing 4.3 - times higher FEC of infection than stallions. Horses bred in studs (3.65±0.289) showed higher FEC than these bred individually (1.28±0.198). There was the effect of pasture type on A. perfoliata FEC, with horses kept on joint pastures (4.06±0.29) showing higher FEC than individuals kept individually (0.88±0.23). Pasture moisture significantly affected A. perfoliata FEC with the highest FECs in horses from watery pastures. Horses bred on dry pastures showed 16 times lower FEC than horses bred on watery pastures. Host age also significantly affected A. perfoliata FEC, with the oldest individuals showing the highest mean FEC. The presented analysis of intrinsic and extrinsic factors may help to overcome A. perfoliata infections in horses in different breeding systems. Understanding the role of management and pasture type risk factors that influence this parasitosis may benefit both breeders and veterinary surgeons.