Why Is My Cat Breathing Fast?

Fast or laboured breathing can point to a serious problem, so learn how to check and when to act.

Quick Answer

Fast breathing in a cat is a sign, not a diagnosis, and possible causes include stress, heat, heart disease, asthma, anaemia, pain and injury.
If your cat is struggling to breathe, panting or breathing with an open mouth, contact a vet immediately, because PDSA calls struggling to breathe a life-threatening emergency.
White, blue or grey gums, collapse, or breathing that is getting rapidly worse mean you should go to the nearest vet straight away and phone ahead on the way.
Sources give different "normal" resting breathing rates, so count breaths while your cat is calm or asleep, keep a log, and ask your vet when a count is too high.
Even if your cat is not struggling, breathing that is quicker or noisier than usual still needs a vet check.

Seeing your cat breathing fast can be worrying, especially because cats hide illness so well. Rapid breathing has the medical name tachypnoea, and it is a sign rather than a diagnosis.

In many cases you will not see any symptoms of a breathing problem until it is quite serious. Therefore, any change in your cat's breathing is worth a check. This guide explains the possible causes, how to count your cat's breathing at home, and when to get help.

Ginger cat asleep curled up on green bedding against a dark red wooden wall – a sleeping cat is the easiest time to spot a cat breathing fast

Possible reasons for a cat breathing fast

Breathing problems can affect cats of any breed or age, and they can quickly become life-threatening. Only a vet can tell which cause applies.

Stress, heat and heatstroke

PDSA lists shock or stress among the causes of breathing problems. VCA Animal Hospitals also notes that normal breathing rates are much higher when a cat is hot, stressed or active.

Heatstroke can leave a cat breathing fast and panting. PDSA says the commonest cause is a cat trapped in a hot space, and it is very unusual for cats to get heatstroke from exercise. If you think your cat has heatstroke, PDSA says to start cooling it down immediately and then contact your vet, and Blue Cross says to contact your vet immediately. PDSA also says not to cover your cat with a wet towel.

Always check sheds, greenhouses, conservatories and cars before you shut them. Never leave a cat in a hot room or car.

Heart disease and fluid around the lungs

PDSA describes fast, shallow, noisy or heavy breathing as often one of the first symptoms of heart disease. Fluid in or around the lungs, from heart disease or cancer, can also make a cat breathe fast.

However, cats often show no signs of heart disease until it is advanced, and signs can seem to appear very suddenly. Some breeds, such as Maine Coons and Ragdolls, are more likely to get one type of heart disease called HCM.

High blood pressure can also thicken the heart muscle over time, and breathlessness and tiredness can be seen. Our guide to blood pressure in cats covers this in more detail.

Asthma and airway disease

International Cat Care lists fast or open-mouth breathing, noisy or wheezy breathing and bouts of coughing as signs of asthma or chronic bronchitis. An asthma attack can be life-threatening, so it is an emergency.

Being overweight can also worsen breathing difficulties in cats with asthma. PDSA also lists cat flu and other respiratory infections among the causes of breathing problems.

For more on these conditions, see our guides to cat asthma and coughing in cats.

Pale grey Scottish Fold-type cat resting with its eyes closed by a window – a calm, resting cat is the right time to notice a cat breathing fast

Anaemia, pain and other causes

Anaemia means a low red blood cell count. International Cat Care lists pale gums, weakness and tiredness among the signs of anaemia, and says that, especially when severe, it is likely to cause a fast heart rate and fast breathing.

Vets Now also lists infection, trauma and bleeding, inhaled foreign objects, allergies, pain, fever, medication, tumours and a bloated belly. PDSA adds that flat-faced breeds, such as Persians, often have breathing problems because of their face and nose shape.

Blue Cross lists heavy or fast breathing among the signs of a road accident. It advises contacting a vet after a road accident or a fall even if your cat looks unhurt, because there may be internal injuries that are not obvious.

How to count your cat's breathing rate at home

If your cat is struggling to breathe, do not stop to count. Go straight to the emergency signs below and contact a vet immediately.

The resting respiratory rate is the number of breaths your cat takes in a minute while resting or sleeping. A calm home count can show your vet how the heart and lungs are working without the effects of stress, excitement or exercise.

Wait until your cat is relaxed and resting or sleeping. Do not count while it is dreaming, because dreaming often speeds up breathing.
Do not count while your cat is purring.
Keep a good distance. Each rise and fall of the chest is one breath.
Count for 15 seconds and multiply by four, or time a whole minute if you prefer.
Write the result down. If it looks high, count again a few times over the next couple of hours.
If the rate stays high, contact your vet as soon as possible. A short phone video of unusual breathing can also help.

What is a normal resting breathing rate?

Sources do not agree on what counts as a cat breathing fast at rest, so please do not rely on one number. Here is what each says:

PDSA and the MSD Veterinary Manual both give 16 to 40 breaths per minute for a resting cat.
Vets Now says a normal cat takes 20 to 30 breaths per minute.
The Cornell Feline Health Center (a US source) gives 15 to 30, and says rates above 35 should prompt a call to a vet.
VCA Animal Hospitals (also US) says resting or sleeping rates that are consistently over 30 are increased, and that for some cats a lower rate may count as raised.

For a cat with the heart disease HCM, PDSA says the sleeping rate should be below 35. It says a higher rate could mean the heart is struggling, and your vet should hear about any rise.

So count the resting rate, keep a log, and ask your own vet what count is too high for your cat. Call your vet if the rate is consistently raised or the breathing looks like an effort.

Emergency: Contact a Vet Immediately If…

Your cat is struggling to breathe, or is unable to breathe.
Your cat is panting or breathing with an open mouth. PDSA says cats open their mouths to breathe if they are really struggling.
The gums look white, blue or grey.
Your cat has collapsed, or its breathing is getting rapidly worse.
Your cat's belly moves as well as its chest with each breath, its nostrils flare, or it stretches out with its head and neck held low and out in front to breathe.
You think your cat is having an asthma attack.
Your cat is breathing heavily or fast after a road accident or fall, even if it looks unhurt.

Call your vet or the nearest out-of-hours emergency vet straight away, and phone on the way so they are ready. Keep your cat as calm and cool as you can, and avoid unnecessary handling, because stress makes breathing worse.

When to Contact Your Vet

Your cat has mild breathing symptoms but is not struggling. PDSA says coughing, sneezing, a runny nose, weepy eyes, not eating or low energy still need a vet appointment.
The breathing settles once your cat calms down, but it is quicker or noisier than usual.
Your cat's resting or sleeping count is consistently raised.
Your cat already has heart disease, asthma or another breathing condition, and its breathing changes.
You are simply worried about your cat's breathing.

Never wait to see if things improve. The faster a cat is treated, the better its chance of survival.

How vets find the cause

Your vet will ask about the history, watch how your cat breathes and listen to the chest for a murmur or fluid. They will also check the gum colour, which shows oxygen delivery and possible anaemia. Blood tests, X-rays or an ultrasound scan may follow.

A cat that is struggling may be admitted straight away for oxygen and time to settle before further tests. If asthma is suspected, tests can include looking into the airways with a camera, and most of these need an anaesthetic. For heart disease, checks include an ECG, a heart ultrasound, X-rays and blood pressure.

Treatment depends on the diagnosis, and most breathing problems need hospital admission until breathing has improved. Asthma is usually managed with daily medication, and many cats with heart disease are managed with medicines and close monitoring.

Please do not give your cat any human medicines. Blue Cross warns that they are highly toxic to cats.

How Pet Med Direct Can Help

Pet Med Direct is an online pet pharmacy, not an emergency service. Breathing difficulty needs a vet straight away, so please do not wait for an order to arrive.

If your vet later prescribes medicine for your cat, you can read how pet prescriptions work or browse our cat medication range. Ongoing medicines can be ordered through repeat pet prescriptions.

Some pet medicines require a valid veterinary prescription. Pet Med Direct can only supply prescription medicines after the prescription has been checked. Always follow your vet's advice and the directions on the medicine label.

Frequently Asked Questions

What is a normal breathing rate for a cat?

Sources differ. PDSA gives 16 to 40 breaths per minute, Vets Now gives 20 to 30, and Cornell gives 15 to 30. Ask your own vet what count to worry about for your cat.

Is it normal for a cat to pant?

No. PDSA says cats nearly always breathe through their nose, so panting or mouth breathing is a sign that a cat is either extremely stressed or really struggling to breathe. It says never to ignore a breathing problem, especially mouth breathing, and to contact your vet immediately if your cat is panting.

Why is my cat breathing fast while sleeping?

Dreaming often speeds up breathing, so count again once your cat is settled. If the sleeping rate stays high on repeated counts, contact your vet as soon as possible.

Can stress make my cat breathe faster?

Yes. PDSA says stress makes breathing worse, and VCA notes that rates are much higher when a cat is hot, stressed or active. Recount when your cat is calm, and see a vet if the rate stays high.

Does fast breathing always mean heart failure?

No. The causes are many, from stress and heat to asthma, anaemia, infection and injury. Only a vet can work out which one applies.

Should I wait and see if the breathing improves?

No. PDSA says never to wait to see if things improve, and even mild signs that settle should still be checked.

Why does my vet want me to count the rate at home?

PDSA says your vet may ask for the count to get an idea of how your cat's heart and lungs are working when they are not affected by stress, excitement or exercise. Regular counts also let your vet see whether anything changes over time.

Related Cat Health Guides

Sources and Further Reading

This article was researched from the sources listed above. It is general information for cat owners and is not a substitute for advice from your own vet.

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This article is for informational purposes only and does not constitute veterinary advice.
If you are concerned about your cat’s health, please consult a qualified veterinarian.