Abstract

A retrospective review of specimens submitted to the Comparative Ocular Pathology Laboratory of Wisconsin (COPLOW) was performed to describe the type and relative frequency of ocular disease in these animals. Eighty-five submissions were reviewed from three separate databases all housed in the COPLOW laboratory. Based on the microscopic findings, eyes were separated into the following categories, which are not mutually exclusive: normal, non-inflammatory corneal disease, metastatic cancer, amyloid, phthisis bulbi, keratitis, cataract, and trauma. Results are presented for each individual regardless of whether one or two eyes were submitted. Six distinct species are represented but the California sea lion alone accounted for 56 submissions, 33 of which had normal eyes. Abnormalities were seen in 52 specimens: 6 with metastatic cancer, 4 with amyloid, 6 with phthisis bulbi, 6 with keratitis, 4 with cataract only, 5 with traumatic disease, and 25 with corneal disease not primarily inflammatory. Among those in the final category, 8 had only epithelial changes, 2 had only endothelial attenuation, 8 had only stromal changes and 7 had complicated disease with features of all categories. Corneal epithelial changes consisted of epithelial attenuation, poor attachment, and disorganization or dysplasia. Stromal changes were always hypercellularity and loss of the lamellar organization. Endothelial changes were attenuation often with rupture of the very delicate Descemet's membrane. It was expected that non-inflammatory corneal pathology would be the most common finding considering clinical reports of corneal disease in pinnipeds. The presence of pathology in all anatomic segments of the cornea suggests a primary degenerative process of unknown pathogenesis. This is the first report of ocular amyloid in pinniped eyes. The presence of metastatic cancer in 6 individuals suggests it is a fairly common finding.