The basal metabolic rate (BMR) is critical to determining appropriate dietary energy requirements in dogs. In a study published in the Journal of Animal Science, researchers examined how multiple variables affect BMR in working Labrador Retrievers, offering insights for more personalized pet nutrition.
The study used open-circuit indirect calorimetry on 96 Labradors to assess resting BMR and utilized DXA scans to evaluate body composition in 33 of them. Dogs were grouped by age (young, adult, senior), sex, and reproductive status (intact or altered). The mean BMR was 130 (27) kcal/kg0.75.
Sex differences were significant: males averaged 136 (28) kcal/kg0.75 vs. females at 125 (25) kcal/kg0.75 (P = 0.045). Similarly, intact dogs had higher BMRs than neutered/spayed dogs (121 vs. 109 kcal/kg0.75, P < 0.001).
Age impacted BMR as well. Young (6 months–2 years) and adult (3–6 years) dogs both had significantly higher BMRs—136 and 135 kcal/kg0.75, respectively—than senior dogs (7+ years), who averaged 120 kcal/kg0.75.
Body composition also played a clear role. BMR decreased with higher fat mass (P < 0.001) and increased with more lean muscle (P < 0.001). Additionally, BMR showed a negative linear relationship with environmental temperature (R2 = 0.51), with elevations occurring in both extreme cold (< 5°C) and heat (> 35°C).
These findings underscore the importance of tailoring diets to a dog’s specific demographic profile. The study supports development of energy-specific feeding plans that factor in not only breed, but also age, sex, reproductive status, muscle mass, and living conditions.
Source: J. Varney, J. Fowler, J. Weil, C. P. N. Watson, M. Boggess, C. Coon. “PSI-B-41 Late-Breaking: Effect of age, sex, reproductive status, body composition, and environmental temperature on the basal metabolic rate of working Labrador Retrievers.” Journal of Animal Science, 97, 317–318, 2019-12-05.
