Exploring cardiorespiratory resilience and mobility as indicators of physical fitness under individualised therapy intervals in obese dogs

Obesity in dogs is an increasing health and animal welfare problem as it is associated with numerous secondary diseases and reduced life span. While the causes and consequences of obesity are well documented, the change in cardiorespiratory resilience and mobility parameters in addition to weight loss has rarely been studied. The aim of this study was to analyse the change effects during individualised obesity therapy intervals in accordance with the current state of research on canine obesity and on physical fitness. In a prospective single-arm, non-randomised study without a control arm, 13 obese dogs (Body condition score (BCS) ≥ 7/9) were included. To assess mobility, a submaximal fitness test and gait analysis on a treadmill were performed before and after therapy. The dogs reduced their body weight by 15.26 ± 4.99%. After weight loss, the dogs showed statistically significantly lower heart rates and lactate values, as well as higher pCO₂ and bicarbonate values as indicators of cardiorespiratory resilience. Concerning parameters of mobility, statistically significant changes in the absolute forces and the asymmetrical force distribution were found. The force distribution between the thoracic and pelvic limbs showed a shift towards the pelvic limbs and the symmetry index of the pelvic limbs was lower. The data collected in this study showed how body weight in obese dogs, but also physical fitness parameters change during therapy intervals. The results of this study provide effect sizes to implement standardised submaximal fitness tests and gait analysis as tools for objective monitoring of therapy progress in future studies.