OCULAR FINDINGS IN SLOTH BEARS (MELURSUS URSINUS) RESCUED FROM THE DANCING BEAR TRADE IN INDIA

Abstract

The aim of this study was to descriptively characterize the ophthalmic findings identified in 43 adult sloth bears (Melursus ursinus) rescued from the dancing bear trade in India and examined at two sloth bear rehabilitation centers in Agra and Bannerghatta nr. Bangalore. Animals were selected where ocular disease was suspected except for two bears which were examined while anesthetized for other reasons (fight wound, health check). Full ophthalmic examinations were undertaken under general anesthesia. Ocular ultrasonography, electroretinography, and photography were also performed. Forty-three bears (86 eyes) were examined. Mean Schirmer tear test (STT) = 12+/–6.2 (median 12, 95% CI –0.4–24.4) mm/min. Mean intraocular pressure (IOP) = 11.4+/–3.7 (median 12, 95% CI 4–18.8) mmHg excluding phthisical or grossly hydrophthalmic eyes. Ocular disease perceived to result in uni- or bilateral blindness was common (35 bears) with one or more of the following: phthisis bulbi (19 eyes; 13 bears), cataract (28 eyes; 17 bears), retinal detachment (29 eyes; 21 bears), and retinal degeneration (19 eyes; 16 bears) recorded frequently. Ocular ultrasound recorded mean axial globe diameter in non-phthisical/non-hydrophthalmic eyes as 16.5 +/–1.4 (median 16.4, 95% CI 13.7–19.3) mm and mean axial lens diameter of 4.9 +/–0.1 (median 4.7, 95% CI 4.7–5.1) mm. Blinding ocular disease was common, in particular, phthisis bulbi, retinal degeneration, and retinal detachment. Retinal detachment and phthisis bulbi may relate to blunt force ocular trauma prior to rescue, but ocular tuberculosis (TB) cannot be excluded, and retinal degeneration could result from a poor diet prior to rescue.