Abstract
Not all viral keratoconjunctivitis can be detected by PCR as caused by EHV-2 and 5. The authors therefore compared the prevalence of EHV-2 and 5 by PCR in horses with keratoconjunctivitis and healthy horses. Conjunctival cytobrush samples of 131 horses with suspected viral keratoconjunctivitis between 2001 and 2010 and of 163 healthy horses from three different stables were tested by PCR for the pre- sence of EHV-2 and EHV-5. The prevalence of EHV-2 and 5 is not significantly different in healthy horses and horses with keratoconjunc- tivitis. No specific ophthalmic signs could be attributed to either EVH-2 or EHV-5. The punctate pattern on the corneal surface, which is considered typical for a viral keratitis, was found in horses infected with EHV-2 or EHV-5. It appears, that an EHV-5-infection causes only mild clinical signs compared to horses testing positive for EHV-2. The most severe clinical signs were seen in horse testing positive for EHV- 2 and 5. In this investigation the prevalence of EHV-2 and EHV-5 was similar in healthy horses and horses with keratoconjunctivitis. No sta- tistically significant differences were found. The pathogenicity of EHV-2 and 5 is not clear or very weak.
Sonderegger, Franziska