'Otariid Keratitis' occurs in all populations of eared seals evaluated. A large-scale epidemiological study is ongoing to identify the risk factors that contribute to this disease. Exposure to chronic sunlight appears to be an important risk factor as shade diminishes clinical signs; animals kept out of sunlight the majority of the time have less severe clinical signs. Age may be important since exposure accumulates with aging. Progression of the disease is also associated with secondary opportunistic bacterial and fungal infections. The surface immune system may be imbalanced contributing to these infections and progression.

No abstract

Toxoplasma gondii infection in marine mammals is intriguing and indicative of contamination of the ocean environment and coastal waters with oocysts. Toxoplasma gondii infection was detected in captive marine mammals at a sea aquarium in Canada. Antibodies to T. gondii were found in all 7 bottlenose dolphins (Tursiops truncatus) tested. Two of these dolphins, as well as a walrus (Odobenus rosmarus) at the facility, died. Encephalitis and T. gondii tissue cysts were identified in histological sections of the brain of 1 dolphin (dolphin no. 1). Another dolphin (dolphin no. 2) had mild focal encephalitis without visible organisms, but viable T. gondii was isolated by bioassay in mice and cats from its brain and skeletal muscle; this strain was designated TgDoCA1. The PCR-RFLP typing using 11 markers (B1, SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico) identified a Type II strain. The DNA sequencing of B1 and SAG1 alleles amplified from TgDoCA1 and directly from the brains of dolphin no. 1 and the walrus showed archetypal alleles consistent with infection by a Type II strain. No unique polymorphisms were detected. This is apparently the first report of isolation of T. gondii from a marine mammal in Canada.

We report herein a choroid plexus papilloma in a beluga whale (Delphinapterus leucas). This case was positive for choroid plexus tumor marker Kir7.1 on immunohistochemistry. These results and the high conservation of Kir7.1 across species at the amino acid sequence level strongly suggest that antibodies directed against Kir7.1 not only can be employed for the diagnosis of choroid plexus tumors in cetaceans, but are also likely to be diagnostically useful in other animal species.