Why Is My Cat Panting?

By: Chewy EditorialPublished:

Why Is My Cat Panting?


My 9-month-old male altered cat will pant after lots of play or when anxious (like when being taken to the vet). The vet said he probably had heart trouble, but this is the healthiest, most active young cat you’ve ever seen. He is never ill, rarely slows down and is very affectionate and happy. It’s hard to believe he could be ill. Don’t cats just pant because of activity or stress? I know I’ve had others that did & they lived long lives.


In December 2008, we adopted two black female cats from our humane society. They will be 1 year old in July. When they play hard for a few minutes they open-mouth pant. They do not show signs otherwise of respiratory distress. I have taken them to our vet and she noted inflamed gums, thought that there could be a viral infection and started them on lysine supplements twice a day. I have never really understood how the lysine will benefit them. What do you think? They have good appetites, are playful, active and otherwise seem healthy. I’d appreciate any insight.


I received both of your letters about panting on the same day, so I thought I’d answer you both.

Labored breathing can be a sign of cardiac or pulmonary disease, but panting is different. Panting is usually just a sign of overheating or excitement, whether from playing too hard, or from stress and excitement (for example, a veterinary visit, like you said.)

The fact that your cats do this only after playing or when anxious certainly makes it sound like a case of simple panting, and not something more serious. If no heart murmur was heard on physical exam, and your cats are doing OK, I’d hold off on doing diagnostics such as chest X-rays or cardiac ultrasound for now.

If, however, the breathing seems labored, or if the panting occurs when the cats have not exerted themselves and are totally at rest, I would have the cats evaluated by your vet.

As for the lysine supplementation: Lysine is an amino acid that causes the feline herpesvirus to go dormant quicker. Herpesvirus infections are common causes of upper respiratory disease in cats. I do not know why your vet prescribed the lysine for inflamed gums. If your cat does not have signs of upper respiratory viral infection, you can probably discontinue the lysine.

By: Arnold Plotnick, DVM

Feature image: Greg Brave/Shutterstock.com



By: Chewy EditorialPublished: