How long do cats live with kidney disease?

How long will my cat live with kidney disease?

You've probably already searched this, found a number, and felt worse. So let me give you the numbers properly, with the context that makes them mean something, and then tell you why they matter less than the things you can actually change.

One word about words first. Chronic kidney disease, kidney failure, renal failure, kidney insufficiency: you'll meet all of them, and on this page they're the same condition. The staging system behind the numbers below is explained on the IRIS stages page, and the stage is how the rest of this page is organized.

Read the table carefully. Those are medians, which means half of all cats did better than the number. They come from studies that are getting old, on cats treated with less than we have available today. And the spread around each figure is enormous, which is what the picture below is about.

Stage 1 kidney disease in cats: life expectancy

There's no published median for stage 1, because cats are rarely found this early and the ones who are tend to be followed for other reasons. The honest expectation is years, often many of them.

A stage 1 cat has kidney damage on paper and normal blood values, usually caught by an SDMA result or a urine test. The job here isn't to treat hard, it's to find anything treatable behind the damage, keep an eye on her urine protein and blood pressure, and recheck on a schedule. The temptation to over-treat a cat who feels perfectly well is real, and there's no need.

Stage 2 kidney disease in cats: life expectancy

About three years is the working median, and stage 2 is where most cats are diagnosed.

The figure comes from the largest survival study we have, which followed 211 cats: the ones diagnosed in the upper half of stage 2 lived a median of 1,151 days, just over three years, and the range ran out past eight years. Half of those cats did better than the median, and stage 2 is a wide band, so a cat caught at 1.7 is starting from a better place than a cat caught at 2.7.

This is also the stage where the diet evidence is strongest, and where treating urine protein and blood pressure buys the most. If she was just diagnosed at stage 2, the first 30 days page is the practical version of everything this paragraph implies.

Stage 3 kidney disease in cats: life expectancy

About two years is the published median, 778 days in that same study, and the spread was wide in both directions: the range ran from three weeks to almost six years.

That spread is the important part. Stage 3 is where cats start to feel the disease, and it's also where nearly everything that makes a cat feel better actually works: phosphorus binders, nausea control, subcutaneous fluids, appetite support, treatment for anemia. A stage 3 cat whose phosphorus is at target, whose nausea is handled, and who's eating is set up to be on the long side of that range, and none of those three is luck.

Stage 4 and end-stage kidney failure: how long do cats live?

Usually months rather than years. The published median is 103 days, about three months, and the range in that study ran from a single day to more than five years, so even here the number isn't a sentence.

Two things I'd want you to hold onto in stage 4. First, comfort is very much still treatable: hydration, nausea control, appetite, warmth. Second, a bad week is not automatically the last week. A stage 4 cat who crashes is often dehydrated, constipated, or fighting a kidney infection, and those are fixable, which is why a crash gets investigated before anybody concludes anything. When the question quietly changes from fixing to comfort, the quality of life page is where I've written about telling those apart.

Is she in pain?

Almost everybody wants to ask this and a lot of people don't, so I'll answer it before you have to.

The kidney disease itself doesn't appear to hurt. It makes cats feel unwell rather than sore: tired, queasy, off their food, flat. That's a real kind of misery and it deserves treating, but it isn't pain, and a cat in the early and middle stages is usually not hurting.

What can hurt is the company it keeps, and this is the useful part, because every one of these is treatable on its own:

A sore mouth. Uremic ulcers, or ordinary dental disease that was there anyway. If she approaches food and then backs off, or chews on one side, or drops it, suspect her mouth. It's on the nausea and vomiting page.

Constipation. Common in kidney cats, uncomfortable, and badly under-recognized. If nothing is coming out, that's worth a call rather than a wait.

Arthritis. Most cats her age have some, it goes untreated far more often than not, and it gets written off as her slowing down because of the kidneys. Worth raising specifically, because it's the one on this list most likely to be quietly costing her.

Less often, a kidney infection or a stone, both of which genuinely hurt and both of which need finding rather than enduring.

How you'd know. Cats hide pain, so watch for what changed rather than for complaint: hiding somewhere she never used to, sitting hunched, not jumping to places she always jumped to, a coat going rough because grooming hurts, or flinching when you touch a particular spot.

And the hard rule, because this is where people go wrong at 2am. Never give her a painkiller meant for a person. Ibuprofen and naproxen are dangerous in cats and acetaminophen can kill one, and a leftover anti-inflammatory prescribed for another animal in the house can take a kidney cat's function down fast. There are safe options, and they're a phone call away rather than a cupboard away.

What changes the number

Two cats with identical creatinine values can have completely different years ahead of them, and the difference usually isn't luck.

Whether she keeps eating. This is the single strongest signal, and it's the one you can watch from your kitchen. A cat who eats and holds her weight is in a different situation from a cat who doesn't, regardless of what her stage says. It's also treatable, because a kidney cat who won't eat is usually nauseated rather than finished.

Whether she's losing protein in her urine. Proteinuria shortens the course meaningfully. In the study that established this, cats with a UPC above 0.4 had about four times the risk of dying during the study period compared with cats who weren't losing protein, and even borderline loss carried nearly three times the risk. It's measured as a UPC, it's treatable with a specific drug, and plenty of cats have never had one run. If you want one number to ask for after reading this page, ask for that one.

Whether she eats a kidney diet. The single best-evidenced treatment in this disease. In a two-year randomized trial, none of the cats on a kidney diet died of their kidney disease, against about one in five on ordinary food. An earlier study put it at a median of 633 days against 264, though that one compared cats who took the diet against cats who refused it, and a cat who won't eat is often the sicker cat to begin with, so treat the gap as the direction rather than the size of the effect. The kidney diets page covers how to get it into her, which is the actual hard part.

Whether her phosphorus is controlled. Above target, phosphorus actively damages what's left and makes her feel unwell. It's one of the things we have the most control over, and the target for her stage is tighter than the printed lab range.

Whether high blood pressure, if she has it, is being treated. Between one in five and one in three kidney cats is hypertensive, and untreated it grinds down the remaining kidney tissue. Measuring it needs equipment not every clinic has, including mine, so this is one to ask about rather than assume.

Notice that all five are things somebody can do something about. That's the actual message of this page.

The stage isn't a countdown

A stage describes where she is now. It's a treatment map, and it does that job well. It's a poor predictor and a terrible thing to sit and stare at.

Worth knowing too: stage 2 is a wide band, so a cat at 1.7 and a cat at 2.7 carry the same label and are not in the same position. And a stage taken on a bad day is often a stage too harsh, because dehydration pushes creatinine up. If she was staged on her worst day, ask whether it's worth rechecking now she's stable. I've seen that alone move a cat from a frightening number to a much better one, without anything about her actually changing.

The full explanation, including substaging, is on the IRIS stages page.

What the time actually looks like

The thing nobody tells you when they hand you a median: this disease is mostly ordinary.

Kidney cats aren't sick every day. A well-managed kidney cat sleeps in the sun, complains about dinner being late, sits on the paperwork you're trying to read, and behaves like a cat. There are bad weeks and there are rechecks that come back worse, and in between there's a great deal of normal life.

The decline, when it comes, is usually a slow fade rather than a cliff, punctuated by crises that are often treatable. A bad week is genuinely not always the last week. A cat who's dehydrated, nauseated, constipated, or fighting a kidney infection can feel considerably better in a few days, and that's worth finding out before anybody concludes anything.

What the time actually looks like

Video coming. I'm filming these myself.

What she doesn't know

She doesn't know she has a diagnosis. She isn't counting months, she isn't frightened of what's coming, and she has no concept of her own prognosis.

She takes her reading of how bad this is from how the house feels. That's useful to you, because it means calm and boring is a form of treatment, not just a mood you're trying to fake.

How to stop the number running your week

Practical, because searching this at midnight is a habit and habits need replacing rather than resisting.

Look it up once, then close the tab. You've now done that. There's no further information in the fifth reading.

Replace the search with something that generates real data. Weigh her on Sundays and write it down. That's a number about your cat, it takes ninety seconds, and it's more informative than any median. The monitoring page covers what's worth tracking.

Put the question on the recheck list instead. "Given her last three panels, what would you expect the next year to look like?" is a question your own vet can answer with her actual numbers in front of them. A website cannot.

Notice what the searching is for. Most of the time it's not information, it's wanting somebody to tell you it'll be fine. That's a completely reasonable thing to want. It just isn't in the statistics, and it's worth naming rather than chasing at 2am.

Where the hard part is

At some point, for most cats, treatment stops buying good days and starts buying days. Those are different things, and telling them apart is the hardest judgment in this whole illness.

I won't make that call for you, and I've written properly about how I think about it, including the three-things test, on knowing when it's time. Almost everybody who reads it early tells me they were glad they did it while there was nothing to decide.

For now, though, if she's eating and interested in her own life, the number on this page is not the thing to be thinking about. Her weight on Sunday is.

The studies behind the numbers

So you can see where the figures come from, and how much weight each one will carry. All of them predate SDMA staging and some of what we treat with now, which is one more reason to expect today's cats to do somewhat better.

The survival medians are from Boyd and colleagues, 2008, who followed 211 cats with naturally occurring kidney disease: a median of 1,151 days for cats diagnosed in the upper half of stage 2, 778 days for stage 3, and 103 days for stage 4, with the ranges quoted above.

The urine protein figures are from Syme and colleagues, 2006, who showed survival is tied to the severity of proteinuria: roughly four times the risk at a UPC above 0.4, and nearly three times at borderline levels, compared with non-proteinuric cats.

The diet evidence is Elliott and colleagues, 2000, the 633 against 264 day comparison, and Ross and colleagues, 2006, the two-year randomized trial in which no diet-fed cat had a uremic crisis or died of the disease.

The staging system itself, including the creatinine and SDMA bands in the table, is published free by the International Renal Interest Society, most recently modified in 2026. It's the same document your own vet is working from.