Kidney disease in cats: when to euthanize

It is time to talk about euthanasia when a cat with kidney disease has stopped responding to treatment and is having more bad days than good ones: refusing food for days, vomiting, losing weight fast, too weak to get around, and no longer interested in you or its surroundings. A diagnosis is not that moment, and neither is a number on a blood test. Many cats live comfortably for years after their kidney disease is found.

The decision is made with your vet, who can tell you whether there is anything left to try and what the coming days are likely to hold.

A diagnosis is not the moment

Chronic kidney disease is common in older cats and usually progresses slowly. Vets describe it in four stages using the IRIS system, which is based on blood tests and then refined with blood pressure and urine protein results. Cats in the early and middle stages often feel well for a long time with a kidney diet and treatment.

Even the last stage is not automatically the end. Some cats in stage 4 still eat, groom and look for a lap for a while. How your cat is living matters more than the stage. For the numbers, see cat kidney disease stages and life expectancy, and for the condition as a whole, our guide to chronic kidney disease in senior cats.

What end-stage kidney failure in cats looks like

When the kidneys can no longer clear waste from the blood, it builds up and makes the cat feel sick all the time. Signs of advanced kidney disease include:

• Refusing food for days, including favorite foods and treats.
• Vomiting, drooling or constant lip-licking, which are signs of nausea.
• Severe weight and muscle loss, with the spine and hips standing out.
• Weakness: wobbling, a head carried low, sleeping in one spot all day.
• Dehydration despite fluids, with sunken eyes and dry, sticky gums.
• Mouth ulcers and breath that smells like ammonia, sometimes called uremic breath.
• Pale gums, which can point to anemia.
• A greasy, unkempt coat because the cat has stopped grooming.
• Feeling cold to the touch.
• Twitching or seizures.
• No longer improving with the treatments that used to help.

None of these on its own confirms that the end has come. Several of them together, getting worse in spite of treatment, are what vets mean by end-stage.

Seizures in cats with kidney disease

Seizures can happen in advanced kidney disease. They can point to very high levels of waste in the blood, or to high blood pressure, which is common in cats with kidney disease and can also cause sudden blindness. Seizures have other causes too, some of them unrelated to the kidneys.

A seizure is always a reason to call a vet straight away. High blood pressure can often be treated, so a seizure does not by itself mean nothing more can be done. In a cat that already has the other end-stage signs, though, seizures often mean the body is failing, and many vets will raise euthanasia at that point.

What to review with your vet before deciding

A cat that looks as if it is at the end is sometimes in a crisis that can be turned around: dehydration, a kidney infection, or nausea that has not been controlled. Before you decide, ask your vet whether each of these has been addressed.

• Nausea control. A nauseated cat will not eat however hungry it is. There are anti-nausea medications made for cats.
• Appetite support. Vets can prescribe appetite stimulants, including some that are applied to the skin rather than given as a pill. For some cats a feeding tube is an option.
• Fluids. Fluids given under the skin at home, or through a drip in the hospital during a crisis.
• Diet. A prescription kidney diet is the usual recommendation, but late in the disease your vet may say that eating anything matters more. See what to feed a cat with kidney disease.
• Complications. High blood pressure, low potassium, high phosphorus, anemia and urinary infections each have their own treatments.

Which of these suit your cat, and at what dose, is for the vet to decide. Do not give a cat any human medicine, including painkillers or stomach remedies, unless your vet has specifically told you to. Many are dangerous to cats, and more so when the kidneys are failing.

Two questions are worth asking directly. Is there anything we have not tried that could make her feel better? And if we try it, how soon would we know whether it has worked? A short trial with an agreed end point is easier to live with than open-ended waiting.

A good-days and bad-days method

Kidney disease declines unevenly, which makes it hard to see the trend from inside it. Writing it down helps.

1. Decide now what a good day is for your cat. For example: eats on her own, comes to greet you, uses the litter box, grooms a little, sits in her usual spot.
2. Each evening, mark the calendar as a good day or a bad day.
3. List three to five things your cat has always loved. Note when she stops doing each one.
4. When bad days outnumber good ones, or you get several bad days in a row, call your vet. That is the point to have the conversation, not to keep counting.

If you want something more structured, the quality-of-life scale for senior cats scores seven areas: hurt, hunger, hydration, hygiene, happiness, mobility, and more good days than bad. Bring your scores to the appointment.

A saying that is common in end-of-life care is that it is better a week too early than a day too late. Many owners say afterwards that they wish they had not waited as long as they did.

What happens if a cat dies of kidney failure without euthanasia

It is rarely a quiet slipping away. As waste builds up, the cat feels increasingly nauseated, stops eating and then drinking, and becomes dehydrated and very weak. Mouth ulcers can make swallowing painful. Toward the end the cat grows cold and unresponsive, and some have seizures. This can take days.

That is why most vets recommend euthanasia once a cat has reached this stage and treatment is no longer helping. If you want to care for your cat at home to the end, do it with a palliative plan from your vet and a clear agreement about when you will step in. Euthanasia is only ever performed by a veterinarian and must never be attempted at home by an owner.

The general signs of the final days are described in signs a cat is dying of old age.

Planning ahead

These decisions are easier to make before a crisis than during one.

• Ask your vet what a sudden decline would look like, and who to call after hours. Know where the nearest emergency clinic is.
• Decide between home and clinic. In-home services often need to be booked ahead.
• Decide who will be there.
• Choose aftercare in advance. Our guide to pet cremation costs and options covers the main choices.
• Read what happens during pet euthanasia so that nothing on the day comes as a surprise.

When to call a vet today

Call your vet or an emergency clinic now, whatever stage your cat is in, if you see:

• A seizure, or sudden blindness (wide pupils, bumping into things).
• No food at all for 24 hours.
• Repeated vomiting, or vomit with blood in it.
• Collapse, or being unable to stand or lift the head.
• Straining to urinate with little or nothing coming out.
• Open-mouth breathing or labored breathing.
• Crying out, or pain that does not settle.

Some of these can be treated even in a cat with advanced disease. If they cannot, an emergency vet can still relieve suffering at any hour.

This article is general educational information, not veterinary advice. Kidney disease progresses differently in every cat, and the signs listed here can also come from complications that are treatable. Only a veterinarian who has examined your cat and seen the test results can give a prognosis. The decision about whether and when to euthanize should be made with your veterinarian.