QUERY: Hello, mine is not really a question, just a doubt I've always had about dogs, and I would like to ask a professional veterinary about it. I have always heard people say that dogs sweat through their tongues, but I don't know if it's true or just a myth. I believe my dog sweats just like a human being: his paws (he leaves wet footprints in the floor), his coat is “sweaty” after running... I don't know. I'd be grateful to have it clarified. Thank you (Fernando Flores, Asturias, Spain).
VETS ANSWER*: Well, dogs do have sweat glands, in fact there are two kinds of sweat glands, apocrine (or epitrichial) and eccrine (or atrichial). Apocrine sweat glands are present in the hair coated areas, specially in those with a lower hair follicle density (armpits, interdigital spaces, abdomen, inner thighs); and eccrine sweat glands are only to be found in the footpads. That's why you see your dog sweating.
However, sweating plays a minor role in their thermoregulation, and these glands' function is mainly hormonal, related to pheromones. A dog's primary method of cooling is evaporation through panting. I hope you will find this useful.
* Dr. Jesús M. Melo Carmona (Col. 444. España)