Seroprevalence and factors associated with equine herpesvirus type 1 and 4 in Spanish Purebred horses in Spain.

The research focuses on the prevalence and factors linked with equine herpesvirus type 1 and 4 in Spanish Purebred horses in central Spain. The research aims to fill in data gaps regarding the prevalence of these viruses in Spain and how certain horse and farm characteristics affect this prevalence.

Objective and Methodology

• The study aimed to determine the seroprevalence (presence of specific antibodies in blood serum indicating past exposure to an infectious organism) of EHV-1 and EHV-4 in Spanish Purebred (SP) horses and discover potential horse-level and stud farm-level factors associated with the diseases.
• The study involved serum samples from 334 unvaccinated SP horses from 30 stud farms in Spain. These were collected between September 2011 and November 2013.
• A commercially available EHV-1/EHV-4 antibody ELISA test and seroneutralisation test (reference confirmation test by the World Organisation for Animal Health) were conducted on the samples.
• A questionnaire collected data on various factors potentially influencing seropositivity to EHV-1/EHV-4, which was then examined using logistic regression analysis.

Key Findings

• The standardised EHV-1/EHV-4 seroprevalence in the SP breeding population in central Spain was estimated to be about 53.9%.
• Variables such as increasing age, southern location of the stud farm, temperate summer climate, and a smaller breeding activity surface area were found to be associated with increased odds for EHV-1/EHV-4 seropositivity.
• Conversely, EHV-1/EHV-4 vaccination of other resident horses and separation of breeding mares from youngsters were found to be protective factors.

Implications of the Research

• The study provides critical insights, filling in the data gaps regarding seroprevalence of EHV-1 and EHV-4 in Spain’s Spanish Purebred horse population.
• The identification of various influencing factors associated with an increased or decreased likelihood of EHV-1 and EHV-4 seroprevalence provides a basis for targeted disease prevention measures, including vaccination strategies and control of horse and farm management practices.