A novel zoometric index for assessing body composition in adult rabbits

Obesity is an emerging problem in domesticated rabbits, and an easy-to-use measure of adipose tissue mass is needed. The current study aimed to develop a zoometric ratio, capable of estimating body condition in rabbits. Body weight (BW), body condition score (BCS), and zoometric measures (distal forelimb length, DFL; vertebral length, VL were measured in 150 pet rabbits. Zoometric formulae were created, combining BW with a zoometric measure, and these were tested for their ability to predict adipose tissue mass judged by BCS. Seventy-five (50 per cent) of the rabbits were in ideal condition (BCS 2.5-3.5), 52 (35 per cent) were overweight (BCS>3.5), and 23 (15 per cent) were underweight (BCS<2.5). Median (range) DFL and VL measurements were 12.1 (8.8-16.4 cm) and 34.0 (26.5-50.5 cm), respectively. In rabbits of medium breed size, the BW/DFL ratio was most strongly associated with BCS (Kendall's τ 0.80, P<0.001). Using BW/DFL limits for optimum body condition (eg, minimum 0.16; maximum 0.21), all underweight and overweight rabbits were correctly classified, while only 2/61 (3 per cent) rabbits with an optimum BCS were incorrectly classified as overweight. This study provides preliminary evidence that the BW/DFL might be a useful indirect measure of adipose tissue mass in rabbits of medium breed size.