How being overweight affects lifespan in neutered pet dogs

Abstract

Background There is an association between overweight status and life span in kenneled dogs, but a similar association has not been reported for pet dogs. Objectives To examine the effects of being overweight in middle age on the life span of neutered client‐owned dogs. Animals Fifty‐thousand seven‐hundred eighty seven middle‐aged neutered client‐owned dogs attending a network of approximately 900 veterinary hospitals across North America. Methods Retrospective case‐control study. For each of 12 breeds, groups of dogs aged between 6.5 and 8.5 years were identified as being in “overweight” or “normal” body condition. Within each breed and sex, differences in life span between dogs in normal body condition and overweight body condition in the 2 groups were then analyzed by Cox proportional hazards models. Results For all breeds, instantaneous risk of death for dogs in overweight body condition was greater than those in normal body condition throughout the age range studied, with hazard ratios ranging from 1.35 (99.79% confidence interval [CI] 1.05‐1.73) for German Shepherd dog to 2.86 (99.79% CI 2.14‐3.83) for Yorkshire Terrier. In all breeds, median life span was shorter in overweight compared with normal weight dogs, with the difference being greatest in Yorkshire Terriers (overweight: 13.7 years, 99.79% CI 13.3‐14.2; normal: 16.2 years, 99.79% CI 15.7‐16.5) and least in German Shepherd dogs (overweight: 12.1 years, 99.79% CI 11.8‐12.4; normal: 12.5 years, 99.79% CI 12.2‐12.9). Conclusions and Clinical Importance Veterinary professionals should consider promoting healthy body condition for dogs, particularly from midlife onward.