The aim of this study was to compare the symptoms of a group of horses with ocular disease and EHV - 2 – or EHV - 5 – infection with a group without viral infection. The EHV – positive group consisted of 131 horses, which were presented to the ophthalmology service at the Vetsuisse Faculty Veterinary Teaching hospital between 2001 and 2010. It was further evaluated whether specific symptoms could be related to either EHV - 2 or EHV - 5.
It seems, that an infection with one virus is associated with less severe clinical symptoms than a concurrent infection with both viruses. Additionally, an EHV - 5 – infection causes only mild symptoms.
The group of horses with ocular disease mentioned above was also compared with a group of horses without any ocular problems. This second group consisted of 163 horses from three different stud farms. The purpose of this comparison was to find out if there are differences in the prevalence of the two equine herpesviruses between healthy horses and horses with ocular disease.
In this investigation the prevalences of EHV - 2 and EHV - 5 were similar in both groups. No statistical significant differences were found. This finding warrants further investigations.