5 Reasons Your Cat Could Be Hanging Their Mouth Open

Cat’s faces can go through a wide range of facial expressions. A cat that hangs their mouth open can look funny, but it is not always obvious why they are doing this. Most of the time the cause is normal and not a need for worry. However, there are cases where your cat will keep their mouth open due to pain. We’ve listed four of the most common reasons a cat will keep their mouth open for you to educate yourself on your cat’s behvaiours

To help them smell pheromones

When cats open up their mouths it lets air pass over the roof of their mouth. This area is able to detect sociosexual pheromones.  This basically means that they are responding to any smells that cats use to establish territory through spraying, or the pheromones that a female cat would release during heat.

If your cat is hanging their mouth open, they may have detected another cat’s pheromones in the air. If you have multiple cats or an outdoor cat, this could be caused by spraying about or inside of the house. If you have a male cat that is hanging their mouth open, they may have detected a local female cat that has gone into heat.

Studies have shown that this response is most common in male cats, but female cats can do it too. It’s a very normal behaviour and has no medical issues behind it. Just watch out for increased territorial behaviour that your cat may use to respond to detecting the smells of other cats. You may want to make your cat more comfortable at home. Male cats may also try to escape the house if there is a local female in heat.


Cats may keep their mouth open to cool down when they are too hot. Cats aren’t able to sweat through most of their skin. Panting is one of the few methods that they have to control their temperature. Opening their mouth breathing heavily lets heat to escape through evaporation.

Unlike dogs, cats will only pant in extreme cases when their internal body temperature is way too hot. In a healthy cat, this usually happens after physical exertion like play with a human or fighting with another cat. On a warm day they would usually first try to control their body temperature by seeking shade and resting.

If your cat is hanging their mouth open to pant regularly, it isn’t a good sign for their health, and you should book an appointment with your vet. Regular panting can be a sign of neurological disorders or trauma. As with all medical problems, its best to get a professional’s opinion as soon as possible.

Pain in the mouth

If you’ve ever had tooth pain this is something that you may be able to relate to. A cat’s teeth can go through a lot of wear and tear during play and eating. Sometimes, this can result in chipped teeth or other dental injuries. If these injuries become painful your cat may be keeping their mouth open to relieve some pressure.

Other mouth injuries like cuts and inflammation can cause your cat to keep their mouth open. If your cat is avoiding being pet on the side of their mouth this could be a sign of tooth pains. You may also be able to see signs of injuries to your cat’s mouth if you take a peek inside. Be careful of your fingers as the pain may cause your cat to have redirected aggression.

Winding up for a bite

Cats that are playing will sometimes keep their mouths open as they prepare to take a bite at the object they are playing with. This could be one of their toys around the house or another cat. Depending on a cat’s personality, it could be normal for them to talk up to a toy, prepare to bite it, and then walk away. This is just part of their prey hunting cycle.

Cats that are play fighting together may also keep their mouths open while grappling as they look for an opportunity to sink their teeth in to their play mate. This is also normal behaviour between playing cats. There are other signs that your cat is fighting for real like hissing, excessive swiping, or flattening their ears all the way back.

Other injuries and medical problems

Your cat may be opening their mouth to breath better. This could be due to a blockage in their nose or excessive phsycial exertion. This is particularly common for larger cats and cats that have feline colds or other illnesses. If you think that your cat has respiratory issues, you need to get them checked by a vet as soon as possible.


Cats will keep their mouths open for a range of reasons. These range from normal cat behaviours to medical emergencies so its worth your time to investigate what is going on. Most of the time, the reason for your cat keeping their mouth open is harmless. Male cats will regularly do this when smelling female cats in heat or cat spray around their territory.

Other reasons like panting and fighting as a bit more rare but are okay if they only do it in specific circumstances. Watch out for tooth pain and bring your cat in to see a vet if you think that they are suffering from