title: Keratoconjunctivitis in a group of Icelandic horses with suspected γ-herpesvirus involvement.
abstract: BACKGROUND
  The role of equid γ-herpesviruses on ocular surface diseases has been disputed, because the diagnosis is usually based on clinical symptoms and detection of viral DNA from samples obtained from live animals.
  
  
  OBJECTIVE
  To describe the clinical course, results of polymerase chain reaction (PCR) analysis, in situ hybridisation, cell culture and pathohistological findings of select cases in a presumed outbreak of herpesvirus infection in a group of 15 Icelandic horses.
  
  
  METHODS
  Case series.
  
  
  METHODS
  Pooled ocular and nasal swabs and peripheral blood mononuclear cells of horses diagnosed clinically with herpesvirus-associated keratoconjunctivitis were analysed for presence of equine herpesviruses (EHV)-2 and EHV-5 nucleic acid using real-time PCR. Necropsy specimens from one horse, subjected to euthanasia due to deterioration of clinical symptoms were examined histopathologically, and analysed for presence of EHV-2 and EHV-5 nucleic acid using real-time PCR. In situ hybridisation and cell culture of select samples were performed.
  
  
  RESULTS
  All horses with symptoms of severe keratoconjunctivitis were positive for presence of either EHV-2 and/or EHV-5 nucleic acid using real-time PCR. Assessment of necropsy specimens of the most severely affected case, revealed presence of EHV-2 and/or EHV-5 nucleic acid in several ocular and extraocular anatomical locations. The remaining horses responded favourably to symptomatic treatment.
  
  
  CONCLUSIONS
  This case series illustrates a severe outbreak of keratoconjunctivitis in a group of Icelandic horses, with suspected γ-herpesvirus involvement. For the first time equid γ-herpesviruses were detected in intraocular anatomical locations.
authors.affiliation: Department of Companion Animals and Horses, University of Veterinary Medicine Vienna, Austria.
authors.forename: J O
authors.initials: JO
authors.lastname: Rushton
authors.affiliation: Institute of Virology, University of Veterinary Medicine Vienna, Austria.
authors.forename: J
authors.initials: J
authors.lastname: Kolodziejek
authors.affiliation: Department of Companion Animals and Horses, University of Veterinary Medicine Vienna, Austria.
authors.forename: B
authors.initials: B
authors.lastname: Nell
authors.affiliation: Institute of Pathology and Forensic Veterinary Medicine, University of Veterinary Medicine Vienna, Austria.
authors.forename: H
authors.initials: H
authors.lastname: Weissenböck
authors.affiliation: Institute of Virology, University of Veterinary Medicine Vienna, Austria.|Department of Microbiology and Immunology, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Oman.
authors.forename: N
authors.initials: N
authors.lastname: Nowotny
mesh_terms: D000818:Animals; D018142:Gammaherpesvirinae / Q000302:isolation & purification*; D006734:Horse Diseases / Q000821:virology*; D006736:Horses; D007637:Keratoconjunctivitis / Q000473:pathology / Q000662:veterinary* / Q000821:virology
keywords: EHV-2; EHV-5; Icelandic horse; gammaherpesviruses; horse; keratoconjunctivitis