cat's mouth open and tongue out
Questions About Cats

Why Do Cats Hold Their Mouth Slightly Open?

As such graceful animals, the sight of a cat with their mouth open can seem amusing. Your cat could be using their open mouth to smell something new or may be living with a medical problem.

Why do cats hold their mouth slightly open? If your cat is breathing heavily through their mouth, it is often a sign of sickness. If they are breathing normally, however, they may just have identified an interesting scent. The Jacobson’s organ, found at the back of a cat’s throat, detects smells.

It’s crucial to understand why your cat is holding their mouth open. There is a big difference between experiencing stimuli and underlying health problems.

My Cat’s Mouth is Open and Their Tongue is Out

When your cat opens wide and pokes out their tongue, it’s usually amusing. The truth is, cats stick out their tongues for a multitude of reasons.

The biggest red flag is feline dementia. Senior cats are sometimes unable to keep their mouth closed and tongue in their mouths. This is a symptom of a feline cognitive disorder.

There is no need to panic, though. Some cats open their mouths and loll out their tongues because they’re utterly calm. This is common if your pet is sleeping. In such a scenario, it’s likely that your cat’s jaw has relaxed completely. This will lead to the mouth opening, and the tongue is popping out. If your cat displays no signs of ill health and does this occasionally, it’s perfectly normal.

If your cat is drooling while opening their mouth and poking out their tongue, it’s different. Some common explanations for this behavior include:

Excessive Grooming

This could be a sign of stress in cats, so keep an eye on this. Cats groom themselves to self-soothe. Alternatively, it may just be your pet’s nature.

Dental Problems

Many cats have dental problems during their life. It’s extremely rare for a feline to never run into trouble with their teeth.

High Body Temperature

If it’s very hot and sunny, your cat may find it hard to cool off.

Unwelcome Taste Sensation

If your cat didn’t care for their dinner, that’s one thing. If they have eaten something toxic, however, they’ll need urgent veterinary attention. It may just be that your cat doesn’t enjoy the texture of what they have eaten.

Strong Smells

Your cat may have picked up an interesting smell. They will then open their mouths and poke out their tongues. This is to provide access to the vomeronasal organ, found at the back of the throat. Also known as Jacobson’s organ, this triggers the Flehmen Response.

What is the Flehmen Response?

The Flehmen Response describes a cat’s expression when they discover a new scent. It looks like they are screwing their face in up in disgust. In reality, they are taking in this new smell.

The Flehmen Response is normal in cats, and nothing to worry about. You may notice your pet-engaging in it daily. It is more common in intact males, who always pick up on new feline pheromones. Male cats want to know if somebody is trespassing upon their territory, and find potential mates. This does not mean that female cats never display the Flehmen Response, however.

My Cat is Breathing with an Open Mouth

Typical cat breathing is slow and even through the nose. A healthy feline takes between 20 and 30 breaths in a minute. A relaxed or dozing cat’s breathing will be at the lower end of this scale. If they’re active and alert, it will creep toward the higher side. If you watch your cat’s chest, it should rise and fall in a steady routine.

If your cat is breathing through their mouth, you will need to keep an eye on them. This is not normal behavior for felines, and suggests that they are struggling for breath. The one exception is when a cat concludes a hunt or a play session.

A cat that has undertaken a vigorous cardio workout will breathe through their open mouths. They may even pant. This is your pet cooling off after getting themselves hot and bothered. If your cat wheezes while wandering around or relaxing, however, see a vet.

If your cat is overweight, they’re likely just a little out of shape. This can be managed through diet and exercise. Senior cats, in particular, are prone to diabetes and other weight-related conditions. Here are some tips on how to get an overweight cat to play.

cat keeps mouth open after meowing

Medical Conditions That Cause Cats to Breathe Though Their Mouth

Don’t take any risks if you notice your cat panting or breathing heavily. Unless your pet has just finished some intense physical activity, they should never struggle for breath.

There are numerous health problems that could lead to a cat breathing through their mouth. Let’s take a look at each of them in turn.


Up to 5% of cats have feline asthma. Just like in humans, this can be dangerous if left untreated. A cat inexplicably struggling for breath and constantly coughing may be among this 5%.

Get a formal diagnosis if you suspect they may be asthmatic. There is no cure for the condition, but it can be managed through medication. These are usually corticosteroids (to reduce inflammation) or bronchodilators (to dilate the airways). These drugs may be taken orally, inhaled, or injected.

Pleural Effusion

This condition arises when cats experience a build-up of fluid between their lungs and chest. As Wag Walking explains, there are many explanations for pleural effusion. These include:

  • Over-hydration
  • Hernias
  • Lack of protein due to poor diet,
  • Internal bleeding
  • Bacterial, fungal or viral infections.
  • Cancerous tumors.
  • Organ failure, including the liver, pancreas, and kidneys.
  • Heart failure and blockages.

The threat of pleural effusion means that a cat should always be examined after physical trauma. Don’t wait for symptoms to become clear. Not every health problem connected to an accident manifests itself immediacy and visibly.

If your cat does have pleural effusion, they will need immediate treatment. This usually entails draining the fluid from your cat’s chest using a needle.

If caught early enough and successfully treated, pleural effusion should not return. Your pet may need to undertake some lifestyle changes if they spark the condition, however.

Respiratory Diseases and Infections

Cats can be just as prone to common colds as humans. The most common upper respiratory tract infections in felines are:

  • Feline herpes (FHV-1), which is also known as feline viral rhinotracheitis (FVR)
  • Feline Calicivirus (FVC)
  • Bordetella bronchiseptica (B. bronchiseptica)
  • Chlamydophila felis (C. felis)

If your cat is living with an immunodeficiency disease, they will also likely be struck down.

Treatment for these conditions varies, depending on what your cat is living with. If a bacterial infection causes the problem, your vet will prescribe antibiotics. If your cat has a virus, it will need to run its course.

Whatever course of action you agree upon, your cat will need peace and quiet. They’ll only recover if they can rest, usually for around three weeks. You should also quarantine your cat during this period. Respiratory infections tend to be hugely contagious.

why does my cat open its mouth after I pet it?

Heart Disease

If your cat is struggling with their heart health, heavy breathing will quickly follow. This will be due to fluid building up around the lungs and chest.

As you can imagine, heart disease in felines is serious. If left untreated, it can quickly lead to heart failure – which is frequently fatal.

Aside from heavy breathing, common symptoms of heart disease in cats include:

  • General lethargy and weakness.
  • Paralysis of the hind legs.
  • Fainting and collapsing, especially after physical activity.
  • Elevated heart rate while in a state of relaxation.

At the first sign of any problems with your cat’s heart, see a vet. If caught early enough, heart disease can be managed and your pet’s life prolonged.

Obstructions to the Airways

Your cat may experience any number of obstructions to their airways that make breathing difficult.

These could be hairballs, which occur when your cat grooms themselves and swallows fur. These can be managed by rubbing Vaseline on your cat’s paws, which they’ll lick off. This provides lubrication to your pet’s digestive tract.

Alternatively, your cat may have swallowed something too large to digest. In such an instance, a vet will need to remove the obstruction. They will endeavor to do this with an endoscope to minimize your cat’s discomfort. In some cases, however, surgery may be required to access the blockage.


Cats love the sun, but they can easily have too much of a good thing. Feline skin is paper-thin, and attracts sunlight easily. It may not take long for your pet to get heatstroke. This is especially likely in pets with very thin fur, or long-haired breeds that easily overheat.

If your cat starts panting in the sun, remove them from the heat and encourage hydration. If they show any further signs of ill health, see a vet. Heatstroke and dehydration can be extremely dangerous conditions in felines.

You can also avoid heatstroke by limiting your cat’s time in the sun. Basking indoors by a window should be included in this allowance of sun worshipping. Keep your cat out of direct sunlight between 10 am and 4 pm during hot periods.

My Cat Won’t Close Their Mouth and is Not Eating or Grooming

This is a surefire sign that your pet is experiencing dental pain. All cats are likely to experience problems with their teeth at some point. It becomes more likely in pets older than three years.

Symptoms alongside an open mouth and declining to eat or groom, include:

  • Bad breath
  • Excessive drooling
  • Pawing at the mouth, possibly while verbalizing
  • Swollen or bleeding gums
  • Visibly stained and discolored teeth

It’s vital that a cat’s teeth are cleaned regularly. Once a week should be a minimum routine. You can pick up a feline-specific toothbrush and toothpaste from any pet store. Your cat may not enjoy the process, and they’ll likely resist it at first. Perseverance is essential.

If your cat’s teeth become damaged, they’ll need to be anesthetized for professional cleaning and repair. This is both expensive and potentially dangerous for older pets.

As International Cat Care explains, there are two common warning signs of feline dental problems:

  • Plaque. Plaque is a form of bacteria that builds up over teeth over time. It’s not always immediately visible, as plaque is often transparent. Cleaning teeth regularly will prevent it from taking hold and turning to tartar. Failing to address plaque frequently leads to gum disease.
  • Tartar. If plaque is left untreated, it hardens. This leads to tartar, which resembles hard, yellow staining on the teeth. If your cat has tartar, brushing will rarely be an adequate treatment. Your cat will need to be anesthetized so it can be scraped off with a specialist instrument.

You should always keep an eye on your cat’s teeth. Even if they are pearly white, some breeds are prone to teeth overcrowding their mouth. Additionally, if a cat does not lose all of their baby teeth, new teeth cannot grow.

If any problem is not caught early, periodontal disease will frequently follow.

What is Periodontal Disease?

Periodontal disease is the general term for infection around the teeth and gums. There are three primary forms of periodontal disease.


This is a very common dental complaint that impacts cats of all ages. Gingivitis is essentially an inflammation of the gums around the teeth.

  • Mild gingivitis is caused by plaque starting to build. If your cat’s teeth are cleaned and the plaque removed, mild gingivitis will clear itself up.
  • Moderate gingivitis occurs when the plaque turns to tartar. This could cause some separation between gum and tooth. Your cat’s gum may start to retract in such an instance.
  • Severe gingivitis sees a substantial amount of plaque and tartar inflaming the gums. A vet will need to complete a tooth clean under anesthesia to reverse serve gingivitis. If the gum is too inflamed, tooth extraction may be necessary.


This involves a severe inflammation of the mouth and gums. It’s usually caused by a bacterial infection – possibly from wild prey that your cat has bitten. It can be treated with medication, but must be addressed quickly. Stomatitis will be extremely painful, and could spread to other parts of the body.


This condition is common in senior cats. It is an extremely advanced form of gum disease. The root of your pet’s tooth will become exposed.

This separates tooth from gum, and leaves it loose. Extraction is advisable in the event of periodontitis. The tooth will eventually fall out, but removing it in a controlled setting is safer.

If you suspect that your cat is living with one of these conditions, seek help. They will be extremely painful for your pet, and potentially very hazardous to their long-term health.

My Cat Keeps Their Mouth Open After Meowing

Cast your mind back to when we discussed the Flehmen Response. Does this sound like an accurate representation of your cat’s post-meowing behavior?

If so, you have your answer. Your cat has caught a strange scent, and they are bringing it to your attention. They’re informing you that something isn’t quite normal.

If your cat isn’t reacting to stimulus to their Jacobson’s organ, assess their general health. Pay particular to their teeth. Your cat may be verbalizing physical pain, and are thus unwilling to close their mouths.

cat breathing with an open mouth

My Cat Has an Open Mouth While Stressed

Stress should never be ignored in cats. Despite their independent and confident façade, felines are easily distressed. Changes in routine are the most common explanation. A cat opening their mouth while stressed suggests an accelerated heart rate, which can be dangerous.

Find out what triggers your cat’s discomfort, and do what you can to rectify it. This can be as simple as feeding and entertaining them at the same time every day. Check that their litter box is clean, too.

If your cat seems stressed by their nature, use calming techniques. These include:

  • Ensuring your cat has a room or location that they will never be disturbed. This is your pet’s ‘safe space,’ where they can hide until they calm down.
  • Use a lavender spray or essential oils (if safe!) around the home. While Lavender itself is toxic to felines, they find the scent calming.
  • Play some classical music. This has been shown to reduce stress in cats, and other animals.
  • Reassure your cat that everything is fine.

If the behavior persists, consult a vet. Your cat may need to prescribed anti-anxiety medications.

Why Does My Cat Open Their Mouth After I Pet Them?

Does your cat like to bite and nibble your hands gently? This would explain leaving their mouths open after petting. They are likely awaiting an opportunity to strike.

This behavior is common in kittens and young cats. It can become problematic in older cats that do not outgrow it, though. Cats that are not socialized and still bite as play may not understand limits and boundaries. This means that your cat may accidentally bite too hard, and break the skin. Licking is fine – that’s a message from your cat that they love and accept you. Biting can escalate quickly.

If your pet behaves this way, gently coach them out of considering your hands to be a toy. If they bite gently, subtly remove your hands from their presence. If they bite hard, stop the game and walk away. Don’t tell your cat off – they don’t know any better. Just help them forge a link in their brains that biting means a temporary end to any fun and attention.

You should also play some hunting games with your cat, using toys. This will help your pet work out their hunting instincts without treating your hand as prey.

If your cat holds their mouth open, there is no need to rush them straight to the vet. Take a few hours, or even days, to assess their general behavior and mood. If they only open their mouths when relaxed or detecting a new scent, it’s normal.

Heavy breathing through the mouth, however, is a different story. This should always be assessed as a priority. It doesn’t necessarily mean that your pet’s life is in immediate danger. It does, however, suggest that all is not well with their health. The earlier you seek treatment for sickness, the brighter the outlook of a full recovery.