Acta Vet. Brno 2020, 89: 115-123

Prevalence of equine herpesvirus 2 (EHV-2) in equine ocular disease

Šárka Krisová1, Katarína Tóthová1, Dobromila Molinková2, Zita Makra3, Aikaterini M. Zisopoulou1

1University of Veterinary and Pharmaceutical Sciences Brno, Faculty of Veterinary Medicine, Department of Equine Surgery and Diagnostic Imaging, Brno, Czech Republic
2University of Veterinary and Pharmaceutical Sciences Brno, Faculty of Veterinary Medicine, Department of Infectious Diseases and Microbiology, Brno, Czech Republic
3University of Veterinary Science Budapest, Department and Clinic of Equine Medicine, Budapest, Hungary

Received July 23, 2019
Accepted April 30, 2020

Equine gammaherpesvirus 2 (EHV-2) has been linked to keratitis and keratoconjunctivitis but has also been isolated in horses showing no signs of disease. The aim of the current study was to assess the importance of EHV-2 infection in the aetiopathogenesis of ocular disease, where the applied treatment failed. Seventy-eight horses with nonhealing ocular disease were examined at the Equine Clinic of the University of Veterinary Medicine and Pharmaceutical Sciences, Brno, Czech Republic, between the years 2009 and 2016. In total, 96 conjunctival swabs were taken and, starting from 2014, peripheral blood leukocytes (PBLs) were also examined in 42 patients. Positive EHV-2 results were detected in 53 ocular swab samples (54.64%) and in 22 PBL samples (51.16%). The horses were divided into three groups according to age, up to 3 years, from 3 to 15 years and older than 15 years. Depending on the clinical presentation, horses were also divided into nonulcerative or ulcerative keratitis, keratouveitis, keratoconjunctivitis, and corneal degeneration groups. The group of young horses had a significantly higher ocular swab positivity compared to the middle group (P = 0.01). Increased bilateral ocular occurrence with decreasing age was observed, although it was not significant (P = 0.04). Significant correlation was confirmed between PBL samples and ocular swabs (P = 0.01). This correlation was even higher in cases of bilateral infection. No significant differences were detected when comparing the groups according to the clinical presentation. This study describes the prevalence of EHV-2 in different age group horses with non-healing keratopathies.


This project was supported by the Internal Grant Agency of the Univerity of Veterinary and Pharmaceutical Sciences (project No. 97/2014 FVL).


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