Seroprevalence and factors associated with equine herpesvirus type 1 and 4 in Spanish Purebred horses in Spain.
Authors: Cruz F, Fores P, Mughini-Gras L, Ireland J, Moreno M A, Newton J R
Journal: The Veterinary record
Summary
# Equine herpesvirus in Spanish Purebred horses: seroprevalence and management risk factors Equine herpesviruses 1 and 4 remain significant threats to equine health globally, causing respiratory disease, abortion and neurological complications, yet serological data from Spain's breeding population were limited. Cruz and colleagues surveyed 334 unvaccinated Spanish Purebred horses across 30 central Spanish studs between 2011 and 2013, using ELISA antibody testing confirmed by seroneutralisation to establish exposure prevalence and identify associated risk factors. Over half (53.9%) of the breeding population tested seropositive for EHV-1/4, with seropositivity increasing significantly with age and in studs located in southern regions with temperate summers, whilst smaller farm footprints correlated with higher infection exposure. Vaccination of other resident horses and physical separation of mares from younger stock emerged as protective strategies, suggesting that herd immunity and age-based segregation can meaningfully reduce transmission risk. For practitioners working with Spanish Purebred horses and similar closed breeding populations, these findings support the case for strategic vaccination programmes across studs and careful biosecurity measures, particularly in warmer climates where viral transmission pressures appear greatest.
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Practical Takeaways
- •Over half of unvaccinated Spanish Purebred horses in central Spain have been exposed to EHV-1/EHV-4, indicating endemic circulation—vaccination programmes should be considered for breeding operations
- •Farm management practices matter: separating mares from youngsters and vaccinating other residents on the farm can reduce herd exposure, making these practical biosecurity measures worth implementing
- •Older horses and those on smaller farms in southern regions face higher exposure risk, so targeted surveillance and preventive strategies should focus on these higher-risk populations
Key Findings
- •EHV-1/EHV-4 seroprevalence in Spanish Purebred breeding horses in central Spain was 53.9% (95% CI: 44.0-63.8%)
- •Increasing age and southern farm location were associated with significantly increased seropositivity odds
- •Vaccination of other resident horses and separation of breeding mares from youngsters were protective factors against seropositivity
- •Smaller farm surface area and temperate summer climate were independent risk factors for EHV-1/EHV-4 exposure