An animal's body mass is said to be indirectly related to its rate of heat loss
that is, smaller animals with higher surface area to volume tend to lose heat faster than larger animals. Thus, thermoregulation should be related to body size, however, generalizable patterns are still unclear. Domestic dogs are a diverse species of endothermic mammals, including a 44-fold difference in body size. Previous work in sedentary dogs has determined that body size and other morphological variables tend to predict the thermoregulation of exercising pet dogs. Here, we aimed to address three questions: (1) whether thermoregulatory differences in domestic dogs across seasons are dictated strictly by external environmental temperatures or if individual thermal acclimation is affected by seasonal temperature variation, even indoors
(2) whether athleticism (or training experience) affects or changes thermoregulation in dogs, as it does in humans
and (3) whether thermoregulation in domestic dogs has a genetic basis. We obtained tympanic membrane (T