This research investigated the role of equine herpesvirus (EHV) in idiopathic keratoconjunctivitis in horses. The study also examined how different sample collection methods affect the detection of EHV DNA through quantitative polymerase chain reaction (qPCR). The findings suggested that the presence of EHV DNA did not significantly differ between control and diseased horses. Also, conjunctival swabs were more effective at retrieving viral DNA than conjunctival biopsies.

Aim and Methodology of Study

• This study aimed to understand the relationship between Equine Herpesvirus (EHV) and idiopathic keratoconjunctivitis in horses. It also investigated whether the method of sample collection had an impact on the detection of EHV DNA using a technique known as a quantitative Polymerase Chain Reaction (qPCR).
• To compare marker levels, samples were collected from 12 clinical cases with idiopathic keratoconjunctivitis and six control horses that had been euthanized.
• Sampling methods included taking conjunctival swabs, corneal scrapings, and conjunctival biopsies from the horses. For horses that had both eyes affected, samples were taken from the eye judged to be more severely affected.
• The samples underwent qPCR testing to detect DNA from different strains of EHV, specifically EHV-1, EHV-2, EHV-4, and EHV-5.

Results of the Study

• The study results revealed that the prevalence of EHV DNA did not significantly differ between horses with idiopathic keratoconjunctivitis and the control horses, as assessed by the qPCR technique.
• The research found that the conjunctival swab method was significantly more successful in obtaining viral DNA samples than the conjunctival biopsy. This could have implications for veterinary practices when samples are needed for diagnostic testing.
• The EHV-1 and EHV-4 DNA strains weren’t detected in either normal or affected horses. EHV-2 DNA was found in just two of the 12 horses that had the eye disease, but not in healthy horses. EHV-5 DNA was present in both normal horses and those suffering from idiopathic keratoconjunctivitis.

Conclusions of the Study

• The research concluded that because EHV-5 DNA was regularly found in both affect and unaffected horses, qPCR testing wasn’t a useful tool for the etiological diagnosis of equine keratoconjunctivitis.
• The study results also highlight the efficacy of the conjunctival swab sampling method, which was found to be significantly more successful in yielding viral DNA samples than conjunctival biopsy. This insight could influence veterinary practices in the collection of samples for diagnostic testing.