Keratoconjunctivitis in a group of Icelandic horses with suspected γ-herpesvirus involvement.

The research article investigates an outbreak of a severe eye condition in a group of Icelandic horses, suspected to be caused by a type of herpes virus. The study used advanced testing methods to identify the presence of this virus in sick horses and explored potential treatment responses.

Research Scope and Objective

The principal aim of this investigation was to delve into the clinical progression, findings of polymerase chain reaction or PCR analysis, cellular culture studies, in situ hybridization results, and pathohistological findings in a suspected herpes virus outbreak among a group of 15 Icelandic horses. The focus was on horses diagnosed clinically with keratoconjunctivitis— an inflammation of the cornea and the conjunctiva of the eye—believed to be associated with the equine herpes viruses EHV-2 and EHV-5.

Methods Used in the Research

• Investigators made use of a case series methodology, gathering and analyzing data from a specific cluster of horses affected by the outbreak.
• Pooled ocular and nasal swabs, along with peripheral blood mononuclear cells from diagnosed horses, were analysed. These tests were geared towards identifying the presence of nucleic acid indicative of the two suspected equine herpes viruses.
• A necropsy, or post-mortem examination, was performed on one horse which had to be euthanized due to worsening clinical symptoms. This allowed for histopathological examination and further real-time PCR analysis for viral detection.
• Additional in situ hybridization and cell culture tests were conducted on selected samples.

Research Findings

The research unveiled that all the horses with symptoms of severe keratoconjunctivitis tested positive for either EHV-2 and/or EHV-5 nucleic acid via real-time PCR. Closer inspection of the post-mortem test results revealed the presence of these herpes viruses in several ocular and extraocular anatomical locations in the most severely afflicted horse.

On a positive note, the remaining horses showed favourable responses to symptomatic treatment.

Research Conclusion

In summary, the researchers outlined a significant outbreak of keratoconjunctivitis in a group of Icelandic horses, with suspected γ-herpesvirus involvement. Exceptionally, the study discovered equid γ-herpesviruses in intraocular anatomical locations for the first time, adding a new understanding to the potential impacts of these viruses.