Modification of Domestic Animal Lameness Scales for Use in Asiatic Black Bears (Ursus thibetanus)

Lameness in animals is a welfare concern as it can be an indicator of pain. A standardized bear lameness scale would significantly improve the ability of facilities that house bears to monitor, manage, and treat lameness in their animals. The Animals Asia bear rescue center in Vietnam holds over 180 rescued bears with varying health and mobility conditions as a result of the illegal bear bile trade, and a reliable lameness assessment system was needed. Bear locomotion includes a lumbering gait, which differs from domestic animal locomotion, necessitating the modification of domestic animal lameness scales, and a five-point lameness scale was developed. Professionals from various veterinary-related backgrounds scored bear lameness videos to assess interobserver reliability and the intraclass correlation coefficient indicated good to excellent reliability. A 15-min training video with examples of lameness and grades was provided before assessment. The lameness scale developed herein addresses the lack of a published lameness scale for bears, and, due to the similar locomotion of the genus, can be used on any bear species. This scale is a consistent and reliable tool for evaluating and documenting lameness in addition to monitoring response to treatment. It will benefit bear welfare by indirectly characterizing the level of pain a bear is experiencing due to lameness as well as serving to document trends in pain status.