You might know panting helps regulate body temperature, but why do dogs pant to cool down? It comes down to their lack of sweat glands, says Jessa Paschke, behavior and training specialist with Mars Petcare North America. Read on to find out more!

She’s suffering heatstroke

Panting after running around or spending time in the sun usually isn’t anything to worry about, but keep an eye out for heat stroke if it’s been a particularly hot day. A dog that’s panting excessively and is also acting lethargic or confused, vomiting, drooling, or showing reddened gums might be overheating, says Paschke.

Get your dog to the vet pronto if you suspect heatstroke, and help your pet cool down in the meantime, says Gary Richter, DVM, holistic pet veterinarian. He recommends getting your dog out of the heat and rinsing her with room-temperature water—ice will actually work against your pet.

‘The ice is so cold that it causes the blood vessels in the skin to restrict, and circulation is not as effective,’ he says. ‘Room temperature … will ultimately help them cool down quicker and better.’

He’s feeling playful

A dog that’s running around might not just be cooling himself down from all the exercise, but it could also be signaling that he’s excited. ‘When playing … some dogs may have a very pronounced pant, often sounding like a staccato-type of wheezing, which is known as ‘dog laughter,’’ says Paschke.

‘During dog laughter, a dog will display loose body language, which helps to distinguish it from more serious types of panting, such as heat stroke.’

She has laryngeal paralysis

Like humans, dogs’ larynxes (aka voice boxes) keep their airways covered when they swallow to keep food and water from getting into their lungs. But as older dogs age, it’s not uncommon for their larynx to stop moving, says Dr. Richter.

‘Dogs lose the ability to move those pieces of tissue and wind up with a physical obstruction over their airways when they’re breathing,’ he says. Because the larynx also affects voice, you might notice hoarseness or a change in the sound of your dog’s bark, along with labored breathing.

He’s having trouble breathing

A slew of respiratory issues, including allergic reactions, pneumonia, and bronchitis, might make your dog sound like he’s panting more than usual. ‘There’s panting—increased respiratory rate—but then there’s increased respiratory effort, like it’s harder for them to actually breathe,’ says Dr. Richter. ‘It can be subtle, but there’s a definitive difference.’ Talk to a vet about what’s behind your dog’s heavy breathing and what treatment options you have.

She has heart trouble

Not only can lungs and airways affect your dog’s breathing, but cardiovascular trouble can, too. Heart disease sometimes makes fluid build up in a dog’s lungs, making your pet pant as it struggles to breathe, says Dr. Richter.