End-stage congestive heart failure in cats: when is it time?

End-stage congestive heart failure in a cat means the fluid keeps coming back even though the medicines have been raised as far as the vet can safely take them. The usual signs are a breathing rate that stays high at rest, breathing with effort or with the mouth open, refusing food, muscle loss and weakness. At this stage treatment is buying a limited amount of time, and it is the right point to talk with your vet about euthanasia.

It is time when your cat can no longer breathe comfortably at rest in spite of treatment, or when what it takes to keep it breathing, such as repeated chest drains and hospital stays, costs the cat more than it gives back. Your vet makes that judgment with you.

What end-stage heart failure looks like in a cat

In congestive heart failure the heart cannot move blood forward well enough, and fluid backs up into the lungs or into the chest around them. In cats the cause is most often a disease of the heart muscle, such as hypertrophic cardiomyopathy. Our guide to congestive heart failure in senior cats covers diagnosis and treatment from the start.

Signs that the disease is reaching its last stage include:

• A resting breathing rate that stays high, or keeps creeping up, while on medication.
• Breathing with effort: the belly heaving, elbows held out, neck stretched forward, crouching upright and refusing to lie on one side.
• Open-mouth breathing or panting. In a cat with heart disease this is an emergency.
• Fluid that returns quickly after it has been drained, or in spite of higher doses of diuretic.
• Refusing food, with weight and muscle loss along the spine and hips.
• Weakness: hiding, no longer grooming, tiring after a few steps, fainting or collapsing.
• Cold ears and paws, and gums that look pale, gray or bluish.
• Sudden pain and paralysis in the back legs, which can point to a blood clot.

Cats with heart failure seldom cough the way dogs do. Heavy or fast breathing is the sign to watch, and why an old cat is breathing heavily covers the other causes a vet will rule out.

Counting the breathing rate

Count while your cat is asleep or fully at rest and not purring. One rise and fall of the chest is one breath. Count for 30 seconds and double it.

Many vets use about 30 breaths a minute as the upper limit for a sleeping cat. A count that stays above that, keeps climbing, or comes with any visible effort is a reason to call straight away. Your vet will give you the number to act on for your cat. Write the count down each day, because the trend matters more than any single reading.

Cold back legs or a clot

Cats with heart disease can form a clot in the heart that breaks off and blocks the blood supply to the back legs. It comes on in seconds. The cat cries out, drags one or both back legs, and the paws feel cold, with pads that look pale or bluish.

This is very painful and is an emergency. The outlook after a clot is poor for a cat that is already in heart failure, and many vets will raise euthanasia at that point. Do not wait at home to see whether it passes.

How long can a cat live with end-stage heart failure?

After a first episode of congestive heart failure, commonly reported survival with treatment ranges from a few months to a year or two, and some cats do better than that. Once the failure no longer responds to standard treatment, the time left is usually much shorter, and there is no dependable figure for it. Some cats have days or weeks and some have a few months.

These figures vary a great deal with the type of heart disease, the kidneys and how well the cat takes its medicine. Only your own vet or a veterinary cardiologist can give a prognosis for your cat.

What to review with your vet before deciding

A cat in a breathing crisis can look as if it is at the end and then do well for a while once the fluid is cleared. Before deciding, ask your vet about each of these.

• A recheck. Chest imaging, kidney values, potassium and blood pressure show whether there is room left to adjust treatment.
• The thyroid. An overactive thyroid is common in older cats, strains the heart and can be treated.
• The medicines. The vet may change the diuretic, add another heart medicine or add one that lowers the risk of clots.
• Draining the chest. Removing fluid from around the lungs with a needle brings fast relief.
• Appetite and nausea. Both can often be helped, and a cat that eats copes better with everything else.
• How the medicines are given. If every tablet is a fight, ask whether there are other forms or a simpler schedule.

Which medicines your cat gets, and how much, is for the vet to decide based on its weight, kidneys and other treatment. Do not raise, skip or add a dose on your own unless your vet has given you a plan for exactly that. Never give a cat a human medicine; ibuprofen, naproxen, acetaminophen and aspirin can seriously harm or kill cats.

Two questions are worth asking directly. How long is this change likely to hold? And what will the next crisis look like, and what should I do when it comes?

When treatment stops buying comfortable time

There is rarely one clear moment. Look for these patterns.

• The gap between chest drains is shrinking. Fluid that once took months to return now takes weeks, then days.
• The kidneys cannot cope with the diuretic. Diuretics clear fluid but are hard on the kidneys. Late in the disease the vet is balancing breathlessness against dehydration and kidney failure, and the cat feels sick either way.
• The breathing rate never returns to normal between crises.
• Every trip is an ordeal. Stress makes breathing worse, and a cat that panics in the carrier pays for each visit.
• Your cat will not eat or take its medicine, so the treatment cannot be given.
• Bad days outnumber good ones. The quality of life scale for senior cats helps you score this and take it to your vet.

When several of these are true, ask your vet directly whether euthanasia is now the kind choice. At this stage it is rarely too early.

Why planning ahead matters

Some cats with heart disease die suddenly. For many others the end is a breathing crisis or a clot, which is frightening for the cat and for you, and it often comes at night or on a weekend. A plan made on a calm day spares you from making every decision in an emergency room.

1. Ask your vet now what they expect, and at what point they would advise euthanasia.
2. Find the nearest clinic that is open around the clock. Keep the number and address where everyone in the house can see them.
3. Decide in advance what you will do in the next crisis: treat again, or let your cat go. Tell the people you live with.
4. If you want it done at home, contact a home-visit vet ahead of time and ask how quickly they can come. In a breathing crisis there may not be time to wait, so keep the emergency clinic as the backup.
5. Ask your vet whether there is anything they want you to have at home for a crisis.

Booking a calm appointment on a day when your cat is still comfortable is not giving up. It spares the cat a last crisis. What happens during pet euthanasia describes each step.

Euthanasia is only ever performed by a veterinarian. Never attempt it yourself; see can you put a cat to sleep yourself for why, and for low-cost and at-home options.

Call the vet or an emergency clinic now if

• Your cat is breathing with its mouth open or panting.
• The belly is heaving with each breath, or your cat is crouched with its neck stretched out and will not lie down.
• The resting breathing rate is above the number your vet gave you, or is climbing from one count to the next.
• The gums or tongue look gray, blue or very pale.
• Your cat suddenly cannot use one or both back legs, or cries out in pain.
• Your cat faints or collapses.
• Your cat has not eaten for a day, or cannot be given its heart medicine.

On the way, keep your cat calm and cool in its carrier, handle it as little as possible, and phone ahead so the clinic is ready with oxygen.

This article is general educational information, not veterinary advice. The breathing rates and survival ranges given are commonly used guides, not targets or predictions for your cat, and heart medicines must only be changed on your vet's instruction. Decisions about treatment and the timing of euthanasia should be made with your veterinarian or a veterinary cardiologist.