Characterization of fungal keratitis in alpacas: 11 cases (2003–2012)

Abstract

To describe clinical, microbiological, in vivo confocal microscopic, and histopathologic features of fungal keratitis in alpacas and to estimate prevalence of the disease in a population of alpacas from the northeastern United States. Retrospective case series. Animals-11 alpacas. Medical records of alpacas evaluated by the ophthalmology service of a veterinary teaching hospital were searched to identify animals with a clinical diagnosis of fungal keratitis and positive results for fungal culture of a corneal sample between 2003 and 2012. Signalment and historical, clinical, and microbiological details were recorded. Results of cytologic, histopathologic, and in vivo confocal microscopic corneal examinations were collected when available. Fungal keratitis was diagnosed in 11 of 169 (6.5%) alpacas that underwent ophthalmologic examination by the ophthalmology service during the study period. Ten of the 11 alpacas were evaluated in the summer or fall months. Corneal lesions included stromal ulcer, stromal abscess, corneal perforation, and nonulcerative keratitis. Aspergillus fumigatus and Fusarium solani were the most frequently cultured fungi. Fungi were also identified through corneal cytologic examination, histologic examination, or in vivo confocal microscopy in 9 alpacas. Historically, 2 alpacas were evaluated following external ocular trauma and 1 following corneal foreign body removal. Nine alpacas had received topical treatment with antimicrobials and 2 had antimicrobial-corticosteroid combinations administered topically prior to referral. Nine of 10 alpacas for which follow-up information was available were successfully treated, with globe and vision retention. Fungal keratitis was a relatively common ocular disease in this population of alpacas and appeared to share several clinical features with keratomycosis in horses.