Dogs don't sweat, so they pant as a way to keep themselves cool. When a dog pants, its tongue hangs out of its mouth and the saliva evaporates, cooling the blood that flows just under the surface of the tongue. As the cooled blood moves through the rest of the body, the dog's temperature decreases.
Sometimes a dog's tongue may hang out of its mouth even when it's not panting. This is usually nothing to worry about and simply means that the dog is relaxed. However, there are some cases in which a dog's tongue hanging out of its mouth may be a sign of a medical problem.
Medical conditions that can cause a dog's tongue to hang out of its mouth:
* Dental problems: Bad teeth or oral pain can make it difficult for a dog to keep their mouth closed.
* Respiratory problems: A dog that has difficulty breathing may pant with its tongue hanging out of its mouth.
* Neurological problems: Some neurological conditions can cause a dog to lose control of their tongue muscles.
* Heat stroke: A dog that is experiencing heat stroke may have a swollen tongue that hangs out of its mouth.
If your dog's tongue is hanging out of its mouth and you're concerned that there may be a medical problem, it's important to take them to the vet right away.