For some humans, their sweat is visible only under their arms and forehead, while others seem to be sweating almost everywhere. Sweating is one of the methods our body regulates its temperature. In humans, our sweat glands are spread over most of our body surface. When our internal temperature rises to a detrimental level, sweat provides a slick of moisture over the skin, which then starts to evaporate. As the liquid evaporates, the sweat helps to reduce our body temperature by effectively wrapping us in a thin cool layer.
The dog's skin is completely different, which is the reason why you have not seen a dog with sweaty armpit. Most of the dog's sweat glands are situated around the foot pad. When a dog is overheated, you will sometimes notice a trail of wet footprints left behind as it walks across the floor. Sweat is produced by the sweat organs in the body, which produces watery fluids. The fluid contain substances like proteins and lipids. There are up to 5 million sweat glands situated all through the human body.
If you are wondering “Why do dogs sweat?” This is not a strange thought, because you never see sweat pouring down the dog's face or underarms when the weather is hot and humid. The fact is that dogs sweat, but they have other ways of regulating body temperature than humans. Dogs will sweat through the foot pads and also release heat by panting. They are not able to release body heat as efficiently as humans do because human release body heat by sweating through the skin.
If you observe your dog panting excessively on a hot day, it is because he feels hot and needs to relieve some body heat. By panting, the dog sends fresh air over its tongue and deep into the lungs which alleviate some heat, and they sweat when they are unable to effectively rid themselves of excessive heat and its internal body temperature start to rise.
Dogs do not have the comfort of body cooling because their bodies have very few sweat glands, and most of the sweat glands are in the footpads. They cool themselves mainly through the process of breathing and panting, with the moist lining of their lungs serving as a surface of evaporation.
According to Carrier, in 2011, while checking to ensure the beagles' nails were well trimmed, she noticed something peculiar in several of the dogs. These dogs had paws that were damp — and in some cases, they were even dripping with sweat. She confirmed that dogs actually sweat through their paws!