Determination of the Risk Factors Involved in Lens Diseases in Captive Pinnipeds

Abstract

Purpose: : Pinnipeds have a high incidence of lens diseases. All participating facilities have pinnipeds affected with these problems rendering many blind or requiring lensectomy. In order to evaluate risk factors associated with lens diseases in pinnipeds a questionnaire evaluated various factors.

Methods: : Sixty-six California sea lions were included. All animals were evaluated by a DACVO (SD Denver zoo; CMHC rest). Multivariate statistical analysis (SAS program) was performed.

Results: : Twenty-seven animals are females and 45 are males. Average age of animals is 12.84 years. Fifty/59 animals (84.75%) were raised in captivity, 15.25% (9/59) were beached. Thirty-nine/69 (56.52%) had no history of ocular disease, 30/69 (43.48%) have a history of ocular disease. Seven/47 (14.89%) have parents that were blind, the rest were unknown 40/47 (85.11%). Forty-one of 72 (56.94%) do not have lens disease and 31/72 (43.06%) have lens disease. Variables that significantly contribute to increased risk are: animals ≥15 years of age, history of ocular disease and fighting, lack of shade. Protective variables include tarp shade covering vs cloth or no shade, and shape of the pool.

Conclusions: : Cataracts and lens luxations occur in captive and wild pinnipeds and have genetic and environmental causes especially sunlight. Since cataracts were primarily seen in animals over 15 years of age and they are exposed to chronic sunlight over the course of their lives, implementation of sun protective shade (tarp or other UV protective materials) should help to diminish the development of cataracts in these animals.

Keywords: cataract • radiation damage: light/UV