“Dogs sweat by salivating.”

It's a common sight to see a dog with a wet muzzle and perhaps even drooling a bit when they're hot, leading many to believe that their primary way of cooling down is by salivating. This observation, coupled with the human experience of sweating through skin, has likely fueled the misconception that dogs "sweat" through their mouths. The visible moisture and the dog's apparent discomfort might naturally suggest a direct link between the drool and temperature regulation.

However, the truth is that while saliva can certainly appear when a dog is overheated, it's not their main cooling mechanism. Dogs primarily regulate their body temperature through panting. This rapid, shallow breathing increases airflow over the moist surfaces of the tongue (Review), mouth, and respiratory tract, allowing for evaporative cooling. As water evaporates from these surfaces, it carries heat away from the dog's body, effectively lowering their core temperature.

While dogs do possess sweat glands, these are quite different from human sweat glands and are primarily concentrated on their paw pads. When a dog walks on a hot surface, these glands can release moisture, leaving damp paw prints. This localized sweating helps cool the paws directly and provides some grip, but it's not an efficient way to dissipate heat from their entire body. The visible panting and sometimes accompanying drooling are clear indicators of their most effective and vital cooling process, which is why observing a panting dog is a cue to help them cool down.