Use of starting condition score to estimate changes in body weight and composition during weight loss in obese dogs.

Prior to starting a weight loss programme, target weight (TW) is often estimated, using starting body condition score (BCS). The current study assessed how well such estimates perform in clinical practice. Information on body weight, BCS and body composition was assessed before and after weight loss in 28 obese, client-owned dogs. Median decrease in starting weight per BCS unit was 10% (5-15%), with no significant difference between dogs losing moderate (1-2 BCS points) or marked (3-4 BCS points) amounts of weight (P=0.627). Mean decrease in body fat per BCS unit change was 5% (3-9%). A model based on a change of 10% of starting weight per unit of BCS above ideal (5/9) most closely estimated actual TW, but marked variability was seen. Therefore, although such calculations may provide a guide to final TW in obese dogs, they can either over- or under-estimate the appropriate end point of weight loss.