Virologic survey of dogs with naturally acquired idiopathic conjunctivitis.

Ledbetter, Eric C; Hornbuckle, William E; Dubovi, Edward J

OBJECTIVE To determine the frequency of viral detection in conjunctival samples from client-owned domestic dogs with naturally acquired idiopathic conjunctivitis and to identify signalment, historical, and clinical findings positively associated with viral detection. DESIGN Case-control study. ANIMALS 30 dogs with naturally acquired idiopathic conjunctivitis and a control population of 30 dogs without ocular disease. PROCEDURES Complete physical and ophthalmic examinations were performed for each dog. Conjunctival swab specimens were analyzed by use of virus isolation and PCR assays for the following viruses: canine adenovirus-2 (CAV-2), canine distemper virus, canine herpesvirus-1 (CHV-1), canine parainfuenza virus, canine respiratory coronavirus, infuenza A virus, and West Nile virus. Signalment, clinical, and historical information was recorded and compared between study groups. RESULTS Viruses were detected by either virus isolation or PCR methods significantly more frequently in conjunctival samples from dogs with conjunctivitis (7/30 [23.3%]) than dogs without conjunctivitis (0/30 [0%]). Canine herpesvirus-1 was isolated from 2 conjunctival samples and detected by use of PCR assay in 5 conjunctival samples. Canine adenovirus-2 was isolated from 1 conjunctival sample and detected by use of PCR assay in 2 conjunctiva samples. Sexually intact dogs and frequent exposure to dogs outside the household were positively associated with viral detection in the conjunctivitis group. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that CHV-1 and CAV-2 are common etiologic agents of conjunctivitis in domestic dogs. Risk factors for viral conjunctivitis in dogs reflected increased exposure to other dogs and opportunities for contact with infectious secretions.