6 reasons why your pup is panting and when it's serious

• Dogs pant for a number of reasons, including to beat the heat by cooling themselves down.
• Like humans, dogs may also pant after they've exerted themselves from exercise.
• Panting may also signal a medical issue like Cushing's disease or a heart or lung problem.

Dogs exhibit plenty of interesting behaviors, including panting. This is when they take rapid and shallow open-mouth breaths, usually with their tongue hanging out.

While most of the time panting is harmless and will subside on its own, it's possible that it may signal something more serious, like a heart or lung problem. Since our dogs can't talk to us and let us know how they feel, it's important to take note of any unusual behaviors they may exhibit that may be telling you something.

Here are six reasons why dogs pant and when it might be a sign of something serious.

1. They're hot

The main reason why dogs pant is to cool themselves off, says Dennis Leon, DVM, CCRT, Owner and Medical Director of Willowbrook Veterinary Hospital.

Since dogs don't sweat like humans do, panting helps to evaporate the fluids in the upper respiratory tract, thereby cooling them down and regulating their body temperature, Leon says.

However, be on the lookout for signs of heatstroke in cases of severe heat. "The rule of thumb is that if it's too hot for you to be exercising out in the sun, then it's too hot for the dog," says Leon.

Leon says signs of heatstroke in dogs include:

• Vomiting
• Diarrhea
• Altered behavior
• Collapsing

To help them cool off, be sure to get them to a cooler temperature. You can also spray their paw pads with cold water, says Leon. If your dog continues to exhibit these signs after they cool off a bit, you should take them to the vet as heatstroke can be a medical emergency.

2. They're exerting themselves

"Just like people, dogs will pant when they are exerting themselves," says Gary Richter, MS, DVM, a Veterinary Health Expert with Rover. Examples of exertion could be playing with other dogs at the dog park, going for long hikes, or getting the zoomies.

Panting helps humans and dogs alike get more oxygen into the body, which aids in recovery from exercise, Richter says. The panting should subside once they rest.

3. They're excited

If your dog is excited, such as if they see other people or animals that they're happy about, they may pant and wag their tail, says Richter.

For example, this may commonly happen when you come home from work and reunite with your dog and they are happy to see you. Your dog may also lick you at the same time.

4. They're scared or anxious

On the flipside, negative emotions can cause panting, too. Leon says that fear and anxiety can lead to excessive panting.

Aside from panting, other behavioral symptoms of stress include:

• Putting their ears back
• Putting their tail between their legs
• Yawning
• Licking their lips

If your dog is stressed, Leon says the best thing to do is stop the stressor or physically take your dog away from the stressful environment, and avoid those stressors in the future until a behavior modification plan is put in place.

5. They have a heart or lung problem

If your dog is panting a lot without the above triggers, it can be a sign of something more serious, such as a lung or heart-related illness, such as:

• Congestive heart failure
• Pneumonia
• Bronchitis
• Allergic airway disease
• Cancer

For example, Richter says a dog with a lung problem may pant in order to try to get rid of carbon dioxide and increase oxygen intake.

Similarly, if a dog has a heart problem this can lead to a buildup of fluid in the lungs — which can also mean your dog isn't getting enough oxygen. Richter says other signs to look out for are:

• Coughing
• Gagging
• Low energy
• Collapsing
• Pale or bluish gums

Treatment will depend on the specific diagnosis of what type of heart or lung problem your dog has.

6. They have Cushing's disease

Cushing's disease is an endocrine disease that results in elevated levels of cortisol, a stress hormone, says Leon. The condition is relatively common, with around 100,000 dogs diagnosed annually. Dogs over the age of six are at greater risk. Leon says breeds that seem to be most affected are:

• Poodles
• Dachshunds
• Miniature schnauzers
• Terriers
• Boxers

Along with excessive panting, some telltale signs of Cushing's are:

• Excessive thirst
• Excessive urination
• Hair loss
• "Pot-bellied" appearance

If your dog exhibits these symptoms it's important to take them to the vet for a diagnosis. Blood testing and ultrasound imaging may be necessary, Leon says. A prescription medication called Vetoryl is the main FDA-approved treatment for this condition. It works by reducing the amount of cortisol your dog produces and is typically administered orally for the rest of the dog's life.

Insider's takeaway

In most cases, your dog's panting shouldn't be a cause for concern. However, if they are exhibiting any other concerning symptoms, or excessively panting frequently, it's important to take them to the vet to rule out any serious health conditions and get treatment if necessary.