Background: Obesity is the most common nutritional disease in dogs. Although weight loss by dietary caloric energy restriction is successful in experimental studies, there is limited information on success of such programs in client-owned dogs who are obese. Further, no information currently exists on the changes in body composition during weight loss in clinical cases.
Hypothesis: Key determinants of outcome of weight loss, including energy allocation and body composition, are influenced by both individual and weight program factors.
Animals: Nineteen client-owned dogs with naturally occurring obesity.
Methods: In this prospective clinical study, body composition was quantified by dual-energy X-ray absorptiometry before and after weight loss on an individually tailored program that incorporated a high-protein and moderate-fiber diet.
Results: Mean percentage weight loss was 18% (range, 6-29%), and mean rate of weight loss was 0.85% per week (range, 0.35-1.56%). Mean energy allocation required to achieve weight loss was 60% of maintenance energy requirement at target weight (MERTW) (range, 50-82%). Significant dietary noncompliance was reported (mean, 1.0% MERTW; range, 0.0-9.5%). The mean composition of tissue lost was 84: 15:1 (fat : lean : bone mineral content [BMC]). Lean tissue loss was positively associated with overall percentage of weight loss (Pearson correlation coefficient [Rp] = 0.591, P = .008), whereas BMC loss was greater in retrievers compared with other breeds (1.9% +/- 1.16% versus 0.8% +/- 0.44%; P = .008).
Conclusions and clinical importance: This clinical study demonstrated body composition changes during weight loss in dogs. Conventional programs produced safe weight loss, but marked energy restriction was required and the rate of loss was slower than in experimental studies.