Vernal-like conjunctivitis in a western lowland gorilla (Gorilla gorilla gorilla).

Case Description: A 17-year-old female western lowland gorilla presented with bilateral ocular discharge, conjunctivitis, and rhinitis that was investigated and treated over a 34-month period. Clinical findings, diagnostic results, treatment, and follow-up are described.

Clinical Finding: A mild intermittent mucoid ocular discharge was initially noted. 10 months later, conjunctival hyperemia and thickening developed and progressed rapidly to a mass-like lesion covering the right eye. Hematology revealed eosinophilia. Conjunctival cytology revealed eosinophils and neutrophils, and histopathology revealed a chronic proliferative eosinophilic conjunctivitis. 21 months after, the ocular lesions were investigated the gorilla developed masses within both external nares. Histopathology of the nasal lesions revealed chronic-active eosinophilic rhinitis.

Treatment And Outcome: Treatment of the gorilla was based on protocols recommended for human patients. Protocols for mild, moderate, and finally severe disease were used, involving topical and oral combinations of treatments. The gorilla eventually responded to systemic immunosuppressant therapy recommended for severe refractory disease.

Clinical Significance: To the authors' knowledge, this is the first reported case of vernal-like conjunctivitis in a western lowland gorilla.