Breathing Trouble in a Cat: Red Flags and Why the Clock Matters

Quick answer

A settled cat should breathe so quietly that you have to look for it. Effort you can see across a room is already advanced.

A cat does not pant to cool itself. Dogs do, cats do not, and open-mouth breathing in a cat is not the feline version of a hot dog on a walk. In a cat it points to serious disease of the heart, the lungs or the space around them, and it is an emergency.

Cats also hide breathing difficulty until they run out of reserve. A cat with fluid around its lungs can look almost normal, sitting quietly and eating a little, right up until it collapses. By the time it looks obviously unwell, there is very little time left.

• Open-mouth breathing or panting in a cat at rest is an emergency now, not in the morning.
• Watch effort as well as rate. Belly heaving with each breath, flared nostrils, or elbows held out from the chest all mean the cat is working.
• Count breaths while the cat is asleep. A settled sleeping cat should breathe slowly and quietly, and a consistently fast sleeping rate is one of the earliest warnings there is.
• Blue, grey, white or very pale gums mean go immediately.
• A cat with breathing difficulty can die from being handled. Do the minimum, get it into a carrier, and drive.

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Open-mouth breathing in a cat is an emergency, and there is no wait-and-see version of it.

Unlike dogs, cats do not use panting as a normal way to lose heat. A cat that is breathing through an open mouth at rest is almost always short of oxygen, and the two most common reasons are fluid around the lungs from heart failure and a severe asthma attack. A very brief open mouth after intense play or a frightening car journey, resolving within a minute or two, is the only common benign version, and even that is worth mentioning to your vet. Anything longer, and anything at rest, means going now.
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Do not stress a cat that is struggling to breathe.

A cat in respiratory distress is running on almost no reserve, and the effort of being chased, cornered, held down or wrestled into a carrier can be enough to kill it. Do not open its mouth, do not examine its chest, do not bathe it, and do not give it anything by mouth. Move slowly, use a carrier you can put the cat into from above or whose top lifts off, keep the room quiet and cool, and drive. Phone ahead and say the word "breathing", because that changes how the practice receives you.
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Decide in 60 seconds

The three things to look at

Rate.

Count the rises of the chest for a full minute while the cat is asleep and settled. Not purring, not just after play, not while you are stroking it.

A sleeping cat breathes slowly and quietly. Veterinary cardiologists commonly use a sleeping respiratory rate below about thirty breaths per minute as the reassuring range, and a rate that is consistently above that, or that has clearly climbed compared with this cat's own baseline, is a reason to call.

The value of this measurement is that it changes before the cat looks ill. For a cat with diagnosed heart disease it is the single most useful thing an owner can do at home.

Effort.

Rate can be normal while the cat is working hard, so effort is assessed separately.

Look for the belly wall pushing in and out with each breath, which is called abdominal effort. Look for the nostrils flaring open on each breath. Look for exaggerated movement of the whole chest rather than the small quiet rise of a settled cat.

Effort is the more serious of the two. A cat breathing thirty times a minute with visible abdominal push is in more trouble than a cat breathing forty times a minute quietly.

Posture.

A comfortable cat lies curled or on its side. A cat that cannot breathe adopts a specific position: sitting or lying on its chest, elbows pushed out away from the body, neck stretched forward and head held low, refusing to lie on its side because that makes it worse.

That posture is called orthopnoea and it is one of the most reliable signs of severe respiratory distress in this species. A cat sitting like that is an emergency even if it is quiet and not making a sound.

Counting the sleeping rate properly

Wait until the cat has been asleep for at least a few minutes and is not purring, dreaming or twitching.

Watch the chest, or the flank just behind the ribs. One breath is one rise and one fall together, not two.

Count for a full sixty seconds. Counting for fifteen seconds and multiplying magnifies every error.

Do it on several different nights before you decide what this cat's normal is, and write the numbers down. A single count means little, and a trend across a week means a great deal.

Film it if you are unsure. A ten-second video lets your vet count it themselves, and it removes the guesswork from a phone call.

If your cat has diagnosed heart disease, ask your vet what number should trigger a call. Many will give you a specific figure for that individual cat, and a rise above it is often the first evidence that fluid is accumulating again.

What is usually behind it

Fluid around the lungs.

Pleural effusion fills the space between the lung and the chest wall, so the lungs cannot expand. The breathing becomes rapid and shallow, with effort, and often with an open mouth.

Causes include congestive heart failure, pus in the chest from a bite wound or a penetrating injury, lymph fluid, feline infectious peritonitis, and a mass in the chest. A young cat with a chest mass raises the question of lymphoma, which is why the history and the age matter.

Fluid inside the lungs.

Pulmonary oedema, most often from left-sided heart failure. Rapid breathing with effort, and sometimes pink-tinged froth at the nose or mouth, which is an extreme emergency.

Heart disease.

Hypertrophic cardiomyopathy is the commonest feline heart disease, and it is quiet. Many affected cats have no murmur, no cough and no reduced exercise tolerance that an owner would notice in an indoor cat. The first thing many owners see is either sudden breathing difficulty or a clot lodging at the end of the aorta, which causes screaming and paralysis of the hind legs.

Asthma and chronic bronchitis.

Airway inflammation, narrowing and mucus. The cat coughs, often in bouts, in a crouch with the neck extended, and produces nothing. Between attacks it can look completely well. During an attack it may wheeze, breathe with effort on the way out, and in a severe attack breathe with an open mouth.

Pneumonia.

Infection in the lung tissue, sometimes after inhaling food, liquid, or an oily substance given by mouth. Fever, lethargy and a lack of appetite usually accompany the breathing change.

Trauma.

Air in the chest, bleeding into the lung, broken ribs, or a tear in the diaphragm that lets abdominal organs into the chest. Any cat with breathing changes after a fall, a fight, or a road accident is an emergency even if it walked away at the time.

Upper airway problems.

Cat flu with a blocked nose, a nasopharyngeal polyp, a growth, or a foreign body. These produce noise: snorting, snuffling, or a change in the voice, and often more difficulty breathing in than out.

Severe anaemia.

Not enough red cells to carry oxygen, so the cat breathes faster to compensate. The gums are pale rather than blue, and the cat is weak.

The cough that everyone mistakes for a hairball

This is worth its own section because it is the single most commonly missed feline chest problem.

A cat with asthma crouches low, extends its neck, and makes a repeated retching, hacking effort. It looks exactly like a cat about to bring up a hairball, and owners describe it that way for months.

The distinguishing feature is what comes out. A hairball episode produces a hairball, usually within a few attempts, and then the cat walks off and eats. An asthmatic cough produces nothing, happens repeatedly over days and weeks, and often comes in bouts.

If your cat is "trying to cough up a hairball" more than very occasionally and nothing ever appears, film it and take the video to your vet. Asthma is manageable, and the cats that reach an emergency with a severe attack are frequently cats whose cough had been explained away for a long time.

Checking the gums

Learn your cat's normal gum colour on a healthy day. Do not attempt this on a cat that is already struggling to breathe, because the handling costs more than the information is worth.

Healthy cat gums are pink. Press gently with a fingertip until the colour blanches, release, and the pink should return promptly.

Blue or grey gums mean the blood is not carrying enough oxygen. Go immediately.

White or very pale gums mean shock or severe anaemia. Also immediate.

Yellow gums point to liver disease or red cell destruction and need a same-day appointment.

If the cat's gums are naturally pigmented, look at the inside of the lower eyelid or the tongue instead.

The important caveat: if the cat is already in obvious distress, do not do this. Lifting the lip of a cat that is fighting for air costs it energy it does not have. Go.

Getting to the clinic without making it worse

A carrier whose top comes off, stored where you can reach it in seconds, is worth more in this situation than anything else you could buy.

Phone first and use the word "breathing". Practices triage that word differently from almost anything else you could say.

Use a carrier that opens from the top or whose lid lifts off. Lower the cat in rather than pushing it through a front door. If the only option is a front-opening carrier, tip it onto its end and lower the cat in.

Do not chase or corner the cat. If it has hidden under a bed, tell the practice, because a cat that will not come out and is breathing hard sometimes needs the vet to come to it or needs a different approach.

Keep the car cool and quiet. Radio off, windows up enough to keep it calm, air conditioning on if it is warm.

Put the carrier flat on the floor behind a seat, and do not open it to check during the journey.

Do not cover the carrier completely with a thick blanket. A light cloth over part of it reduces visual stress without reducing airflow.

Do not stop to give food, water or any medication.

Expect the practice to take the cat straight into an oxygen cage before examining it. That is correct, and the delay in getting information is the price of the cat surviving the examination.

What never to do

Never give a cat a human asthma inhaler, cough medicine, antihistamine, decongestant or painkiller. Several are directly toxic to cats and none of them treat what is happening.

Never give leftover medication prescribed for another animal, including diuretics. If your own cat has been prescribed something for its heart with instructions for what to do at home, follow those instructions and phone; otherwise do not improvise.

Never try to open a struggling cat's mouth to look inside or to remove something. Unless you saw the cat inhale an object, you will not find anything, and you will use up reserve it needs.

Never put a cat with breathing difficulty into a bath, a steamy bathroom, or in front of a fan and consider that treatment. Steam is not a substitute for oxygen, and the handling is a cost.

Never assume open-mouth breathing after a car journey is just stress and go home again. Stress is a plausible explanation only if it resolves within minutes and the cat is otherwise entirely normal.

Never delay because the cat has stopped looking distressed. Cats settle briefly and then decompensate, and a quiet cat that was gasping ten minutes ago is still an emergency.

Never assume a normal check-up rules out heart disease. Many cats with significant heart disease have no murmur.

When to get help

This is the target: a cat asleep, breathing so quietly and so slowly that you have to watch carefully to count it.

Go immediately, out of hours, for open-mouth breathing at rest, breathing with visible abdominal effort, flared nostrils, sitting hunched with elbows out and neck extended, blue, grey, white or very pale gums, froth at the nose or mouth, collapse, or any breathing change following trauma.

Go the same day for a sleeping respiratory rate that has clearly risen, breathing that is faster at rest than usual, noisy or snorting breathing that is new, a cat that has stopped eating alongside any breathing change, or a cat with known heart disease whose numbers have moved.

Book within the week for a repeated cough that produces nothing, a change in the cat's voice, persistent nasal discharge, or reduced tolerance of activity.

Tell the practice on the phone what the breathing looks like, how long it has been happening, whether the cat goes outside, whether there has been any trauma or fight, and what the sleeping rate has been. Ask them to be ready with oxygen. In this species, an emergency team that knows what is coming through the door genuinely changes the outcome.