Kidney Disease in Dogs: Signs, Stages and When to Call

For information only. This article supports, and never replaces, an examination by a veterinarian.

Kidney disease in dogs comes in two very different forms. Acute kidney injury strikes suddenly, often after a dog eats something toxic or picks up an infection. It is an emergency, and it can sometimes be reversed. Chronic kidney disease (CKD) creeps in over months or years, mostly in older dogs, and is managed rather than cured.

Chronic kidney disease is quiet. The earliest clue is usually a dog that drinks more and pees more. Most other signs of kidney failure show up only once roughly three quarters of kidney function is gone, which is why routine bloodwork in older dogs matters so much.

If your dog just ate grapes, raisins, antifreeze or someone's pain pills, stop reading and call your vet or a pet poison line now. With kidney toxins, the time to act is before the signs start.

Acute vs Chronic Kidney Disease

Healthy kidneys filter waste out of the blood, keep water and salts in balance, and make a hormone that drives red blood cell production. When they fail, waste builds up and the dog feels sick from it (uremia). Failing kidneys also can't concentrate urine, so water pours out and has to be replaced by drinking.

	Acute kidney injury (AKI)	Chronic kidney disease (CKD)
How it starts	Suddenly, over hours or days	Slowly, over months or years
Usual causes	Toxins, infections, low blood flow, a urinary blockage	Aging, inherited disease, long-term kidney damage, an earlier AKI
Can it recover?	Sometimes, with fast treatment	No, but it can often be managed for years
What to do	Call now	See your vet soon, then regular rechecks

The two overlap. A dog with CKD can have a sudden flare-up, for example from dehydration, and a bad acute injury can leave lasting damage that becomes chronic.

Signs of Kidney Disease in Dogs

Early signs of chronic kidney disease

Drinking more water
Peeing more: bigger puddles, accidents in the house, asking to go out at night
Often nothing else. Many dogs in the early stages look completely normal.

Later signs of chronic kidney disease

Once about three quarters of kidney function is gone, waste builds up and the dog starts to feel unwell:

Poor or picky appetite, weight loss and muscle loss
Vomiting, now and then at first, later more often
Low energy and diarrhea
Bad breath and sores in the mouth
Pale gums, from anemia (a low red blood cell count)
Dehydration, even though the dog drinks a lot

Signs of acute kidney injury

Sudden vomiting or diarrhea
Not eating, very quiet or weak
Dehydration and mouth sores
Peeing much more than usual, much less, or not at all

A dog that has stopped making urine is in serious trouble. Treat it as an emergency.

Early vs late signs of kidney disease in dogs: drinking and peeing more start at about two thirds of function lost; appetite loss, weight loss, vomiting, bad breath, mouth sores and pale gums at about three quarters; sudden signs of acute kidney injury — Infographic by I Love Veterinary

When to Call the Vet

Call now (your vet or an emergency clinic):

Your dog ate or may have eaten grapes, raisins, antifreeze, vitamin D supplements, rat or mouse poison, or human pain medicine, even if they seem fine
Little or no urine
Repeated vomiting, can't keep water down, or won't eat
Weakness, collapse, seizures or sudden blindness
A dog with known kidney disease that stops drinking, starts vomiting or stops eating

See your vet soon: drinking or peeing more, weight loss, a fading appetite, bad breath with mouth sores, or pale gums.

Mention at your next visit: a senior dog with no recent bloodwork and urine test, or a breed prone to inherited kidney disease.

When to call the vet about kidney disease in dogs: call now for grapes, raisins, antifreeze, ibuprofen, naproxen, vitamin D or rat poison, little or no urine, repeated vomiting, collapse, seizures or sudden blindness; see your vet soon for more drinking or weight loss; poison line numbers — Infographic by I Love Veterinary

What Causes Kidney Disease in Dogs?

Sudden (acute) causes

Antifreeze (ethylene glycol). It tastes sweet, and a small amount can kill a dog. Dogs often look drunk at first, then may seem to recover before the kidneys fail, with vomiting, mouth ulcers and sometimes seizures. The antidote only works early. More in our guide to antifreeze poisoning in dogs.
Grapes, raisins and currants. Some dogs develop kidney failure after eating them and others don't, and nobody can predict which dog or how much is too much. Vomiting often comes first, within hours, and kidney failure can follow over the next few days. See can dogs eat grapes?
Human pain relievers (NSAIDs) such as ibuprofen and naproxen.
Too much vitamin D, from human supplements, some rat and mouse poisons, or recalled dog foods (FDA).
Infections, especially leptospirosis, Lyme disease, or a bacterial infection of the kidney itself.
A urinary blockage, or shock with very low blood flow to the kidneys.

Grapes look like a harmless treat, which is exactly the problem. Our list of human foods that are toxic to dogs covers the rest.

Chronic causes

Aging. CKD becomes more common from about 5 to 6 years of age. In older dogs seen at veterinary referral hospitals, it affects up to 1 in 10.
Inherited kidney disease. Some young dogs, mostly under 3, are born with kidneys that never developed properly. Breeds with known inherited kidney problems include the Bull Terrier and West Highland White Terrier (polycystic kidneys), the Chinese Shar-Pei (familial amyloidosis) and the English Cocker Spaniel (a familial glomerular disease).
Other kidney damage. Disease of the kidney's tiny filters (glomerular disease), high blood pressure, long-term kidney infection, stones, cancer, or an earlier acute injury.

In many older dogs, no single cause is ever found.

A young Chinese Shar-Pei at the vet with a bandaged front leg — The Chinese Shar-Pei is one of the breeds that can inherit a kidney disease, familial amyloidosis.

Never Give Your Dog Ibuprofen

When your dog is limping, the medicine cabinet is right there. Leave it shut. The Merck Veterinary Manual says ibuprofen is no longer recommended in dogs, and naproxen (Aleve) is dangerous for dogs too.

These drugs (NSAIDs) block substances the body uses to keep blood flowing to the kidneys when things get tough, such as during dehydration. Take that away and the kidneys can fail suddenly. The FDA also lists stomach ulcers and liver damage.

Vets do prescribe NSAIDs made for dogs, with bloodwork before and during long-term use. If your dog has kidney disease, tell your vet about every medicine and supplement they take.

Ate Something Toxic? Do This Now

Call your vet, an emergency clinic, or a 24/7 poison line: ASPCA Animal Poison Control at (888) 426-4435 or Pet Poison Helpline at (855) 764-7661. A fee may apply.
Don't wait for signs. Grape and antifreeze damage starts before your dog looks sick.
Don't make your dog vomit unless a vet or the poison line tells you to.
Bring the package, and say how much might be missing and when.

How Vets Diagnose Kidney Disease

Bloodwork. Creatinine and BUN are waste products that rise when kidney function falls. SDMA rises earlier, while creatinine is still normal, and is less thrown off by a thin dog's low muscle mass.
Urinalysis. Dilute urine in a dog that should be holding on to water is an early warning. The urine is also checked for protein (the urine protein to creatinine ratio, UPC) and infection.
Blood pressure, which is often high in dogs with kidney disease.
X-rays and ultrasound to look at the kidneys and check for stones or blockages.

One high result is not a diagnosis. A creatinine that keeps creeping up, even inside the normal range, is worth following in an older dog.

IRIS Stages of Kidney Disease Explained

Once CKD is diagnosed, vets stage it with the International Renal Interest Society (IRIS) system, which guides treatment and monitoring. Staging uses fasting creatinine, SDMA or both, measured at least twice in a dog that is well hydrated and stable. One result from a sick day doesn't count.

These are lab results your vet reads from a blood test, not something you can check at home.

IRIS stage	Creatinine (mg/dL)	SDMA (µg/dL)	What it usually means
1	Under 1.4	Under 18	Kidney damage is there (for example, protein in the urine), but waste isn't building up. Usually no signs
2	1.4-2.8	18-35	Mild. Drinking and peeing more may be the only clue
3	2.9-5.0	36-54	Moderate. Many dogs start to look and feel unwell
4	Over 5.0	Over 54	Severe. Higher risk of uremic crises

IRIS dog values (2026) for average-size dogs. Very large or small dogs can differ, and healthy Greyhounds run higher on both tests.

Every stage is also checked for:

Protein in the urine, which is linked to faster progression.
High blood pressure, which can damage the kidneys, eyes, brain and heart. It can detach the retinas, and sudden blindness is sometimes the first thing an owner notices.

Acute kidney injury is graded separately, and that grade can change quickly.

The four IRIS stages of chronic kidney disease in dogs with creatinine and SDMA cutoffs and what owners may see at each stage, plus protein in urine and blood pressure checks — Infographic by I Love Veterinary

Treatment: What the Vet Does

Your vet chooses every medicine and dose.

Acute kidney injury

Dogs with acute kidney injury usually need hospital care:

Treating the cause, for example antibiotics for leptospirosis or the antifreeze antidote when it's caught early.
IV fluids to correct dehydration and keep blood flowing to the kidneys. More is not always better; too much can harm a dog that isn't peeing.
Support for nausea and nutrition, and dialysis for some dogs at specialty hospitals.

Kidneys can recover surprisingly well if the dog gets through the crisis. Dogs with treatable infections tend to do best and dogs poisoned by toxins worst, which is why speed matters.

Chronic kidney disease

CKD can't be cured, so the goals are to slow it down and keep your dog feeling good. Depending on the stage, your vet may recommend a kidney diet, treat high blood pressure and protein loss, control nausea and appetite, keep phosphorus in check, treat anemia and urinary infections, and stop drugs that are hard on the kidneys. Expect regular rechecks of bloodwork, urine and blood pressure.

Diet and Water for Dogs With Kidney Disease

Kidney diets work. Dogs with CKD that eat a veterinary kidney diet, low in phosphorus with moderate high-quality protein, live longer and go longer before a uremic crisis. IRIS recommends them from stage 2.

Cutting phosphorus is the main point. Protein is reduced moderately, not cut to nothing.
Low salt won't fix blood pressure. IRIS notes there is no evidence that it lowers blood pressure in dogs.
Any food beats no food. If your dog refuses the kidney diet, tell your vet rather than letting them skip meals.

Never limit water. Dogs with kidney disease lose water through their urine and must drink more to keep up. Canned food, extra bowls, or water or low-sodium broth on meals can help. Some dogs in later stages need fluids under the skin; only give them if your vet prescribes them and shows you how.

How Long Can a Dog Live With Kidney Disease?

It depends on the type, the stage and the cause, so the outlook varies widely. A dog that survives acute kidney injury can recover partly or fully. Chronic kidney disease usually progresses, but many dogs live for years when it's caught early and managed well; protein in the urine and uncontrolled blood pressure point toward faster progression.

Your vet can tell you what your dog's stage and results mean. Ask about quality of life too: appetite, energy and comfort are what your dog actually feels.

Can Kidney Disease in Dogs Be Prevented?

Most CKD can't be prevented, but it can be caught early. Many acute cases can be prevented:

Keep the toxins above out of reach, wipe up antifreeze spills, and never give a human medicine without your vet's OK.
Leptospirosis can cause sudden kidney injury, and it isn't limited to outdoor or large dogs. Ask your vet whether the lepto vaccine is right for your dog.
For senior dogs, ask about regular bloodwork (including SDMA) and a urine test. Our guide to caring for a senior dog has more.

Questions to Ask Your Vet

Is this acute, chronic, or a flare-up of chronic disease?
What stage is my dog, and is there protein in the urine or high blood pressure?
Which kidney diet do you recommend, and what if my dog won't eat it?
Are any of my dog's medicines or supplements hard on the kidneys?
How often should we recheck, and which signs mean I should call sooner?

Veterinary Cases of Kidney Disease

These cases were shared by veterinary professionals in our community.

Originally written by Arais. Updated by the I Love Veterinary editorial team.

Sources

This article is for general information and is not a substitute for advice from your veterinarian.