Understanding Kidney Failure in Dogs

When a dog’s kidneys start to fail, the effects show up across the whole body, and the signs can be easy to miss until things are already serious. Whether it comes on suddenly or builds slowly over time, kidney failure is a lot to take in. Understanding what’s happening, what to watch for, and what treatment looks like is the best place to start.

What is kidney failure in dogs?

Your dog’s kidneys do a lot of behind-the-scenes work: filtering waste from the blood, keeping fluids balanced, regulating blood pressure, and helping produce hormones that support healthy red blood cells. When they start to fail, that work doesn’t get done, and the effects ripple through the whole body.

One of the trickiest things about kidney failure is that symptoms often don’t show up until a significant amount of kidney function has already been lost. That’s why routine blood work in older dogs isn’t just a formality. It’s genuinely one of the best tools for catching problems early.

Acute vs. chronic kidney failure

There are two distinct forms of kidney failure in dogs, and which one your dog has makes a real difference to how it’s treated and what to expect.

Acute kidney injury (AKI) comes on suddenly, sometimes within hours or days. It’s usually triggered by something specific: a toxin, an infection, or a sudden drop in blood flow to the kidneys. Because the damage is recent, AKI can sometimes be reversed with fast, intensive treatment. Not always, but often enough that acting quickly really matters.

Chronic kidney disease (CKD) is a slower process, where kidney tissue gradually breaks down over months or years. It’s much more common in older dogs and in certain breeds. CKD can’t be reversed. Once that function is gone, it’s gone. But with the right care, many dogs with CKD continue to feel well and enjoy a good quality of life for a meaningful period of time.

Symptoms of kidney failure in dogs

The signs of kidney failure can creep up gradually, especially with CKD. Here’s what to keep an eye out for:

• Drinking more water than usual and urinating more frequently
• Loss of appetite and unexplained weight loss
• Vomiting and diarrhea
• Tiredness and general weakness
• Bad breath with an unusual ammonia-like smell
• Pale gums or sores in the mouth
• In more advanced cases: producing very little urine, or visible fluid buildup

If several of these are showing up together, particularly in an older dog or a breed known to be at risk, don’t wait to call your vet. By the time symptoms appear, the kidneys have often already lost a significant portion of their function.

Causes of kidney failure in dogs

The causes are quite different depending on the type.

Acute kidney injury (AKI) is most often triggered by:

• Toxins: Grapes and raisins (which contain tartaric acid, toxic to dogs even in small amounts), antifreeze (ethylene glycol, found in automotive products), NSAIDs given at the wrong dose, and certain antibiotics
• Infections: Leptospirosis, a bacterial infection dogs can pick up through contaminated water or soil, is one of the most common infectious causes
• Reduced blood flow to the kidneys: From dehydration, a cardiovascular event, or complications during surgery
• Urinary blockages: Which cause back-pressure that damages the kidneys over time

Chronic kidney disease (CKD) tends to develop because of:

• Age, as kidney tissue naturally diminishes over time in older dogs
• Breed predispositions, including English Cocker Spaniels and Bull Terriers
• Dental disease, as chronic oral bacteria can affect kidney health over time
• High blood pressure
• Immune-mediated diseases
• Long-term effects from a previous AKI

Diagnosis of kidney failure in dogs

Your vet will start with blood tests and a urine sample. Here’s what they’re looking for:

• Creatinine and BUN (blood urea nitrogen): Waste products that build up in the blood when the kidneys aren’t filtering properly. Elevated levels are a key sign something’s wrong.
• SDMA (symmetric dimethylarginine): A newer, more sensitive marker that can detect early kidney disease before creatinine levels even start to rise.
• Urinalysis: Dilute urine or protein in the urine both signal that the kidneys aren’t doing their job properly.

From there, your vet might also recommend a kidney ultrasound to check the structure of the kidneys, blood pressure testing, or in complex cases, a biopsy. For dogs with CKD, your vet will use the IRIS staging system, a 4-stage scale based on bloodwork that helps map out how advanced the disease is and what treatment makes sense at each stage.

Treatment of kidney failure in dogs

For AKI:

The priority is stabilizing your dog and giving the kidneys the best chance to recover. Here’s what that typically looks like:

What’s used	Why it helps
IV fluid therapy	Think of it as flushing the system. Fluids help clear toxins from the blood and get your dog rehydrated as quickly as possible
Treating the underlying cause	Whether it’s a toxin, an infection like leptospirosis, or a blockage, addressing the root cause is always the first priority
Close monitoring	Kidney values are checked regularly so your vet can see whether the kidneys are responding and adjust treatment accordingly
Dialysis	A last-resort option for the most severe cases, only available at specialist and veterinary teaching hospitals, but it can be life-saving when other treatments aren’t enough

For CKD:

There’s no way to restore kidney function that’s already been lost, but the right management plan can slow things down and keep your dog feeling like themselves for longer. Here’s what that usually involves:

What’s used	Why it helps
Prescription renal diet	A specially formulated food that reduces the kidneys’ workload by lowering protein and phosphorus. One of the most impactful things you can do at home
Subcutaneous fluids	Fluids given just under the skin, which many pet parents learn to do at home. Helps keep your dog hydrated between vet visits
Medications	Can include anti-nausea drugs, phosphate binders, and blood pressure medication depending on what your dog needs
Managing secondary complications	As CKD progresses, issues like anemia can develop. These are treated alongside the kidney disease itself
Regular check-ins	Routine bloodwork lets your vet track how things are progressing and catch changes early enough to act on them

Prognosis and life expectancy

This is the question most pet parents want answered first, and it deserves a straight answer.

For AKI, a lot depends on the cause and how quickly treatment was started. Dogs with leptospirosis-related AKI often recover well with prompt care. AKI caused by antifreeze ingestion is more serious. The prognosis is much better when caught and treated early, but can be grave if treatment is delayed.

For CKD, how long a dog lives after diagnosis varies a lot depending on what stage the disease is at when it’s caught. According to research published in Today’s Veterinary Practice, dogs diagnosed at an early stage (Stage 1) have a median survival of over a year. By Stage 2, that range is roughly 7 to 13 months. Stage 3 drops to around 4 to 7 months, and Stage 4 to as little as two weeks to three months. Those are averages; some dogs do considerably better, especially when the disease is well managed. The earlier it’s caught, the more time and options you have.

It’s worth having an honest conversation with your vet about what stage your dog is at, what to realistically expect, and what signs to watch for as things change.

Does pet insurance cover kidney disease?

Yes. Kidney disease, including both chronic kidney disease (CKD) and acute kidney injury (AKI), is covered under Lemonade Pet’s base accident and illness policy, as long as the condition isn’t pre-existing. That includes eligible costs like diagnostic testing, hospitalization, IV fluids, medications, and the ongoing monitoring that’s typically part of managing kidney disease long-term.

Kidney disease often means a sustained commitment to care: regular bloodwork, frequent vet visits, and adjustments to treatment as the condition progresses. Having coverage in place before any symptoms appear means that as things evolve, cost isn’t the thing driving your decisions.

Before we go

Kidney disease is one of those diagnoses that asks a lot of you as a pet parent, but caught early and managed well, many dogs live comfortably for months or even years after diagnosis. Staying in close contact with your vet and keeping up with regular monitoring are the things that make the biggest difference. If you don’t have a pet insurance policy in place yet, it’s worth taking a few minutes to explore your options. Getting a quote is straightforward, and having coverage before anything develops puts you in a much stronger position when it matters most.

Frequently Asked Questions

A few quick words, because we <3 our lawyers: This post is general in nature, and any statement in it doesn’t alter the terms, conditions, exclusions, or limitations of the policies issued, which differ according to your state of residence. You’re encouraged to discuss your specific circumstances with your own professional advisors. The purpose of this post is merely to provide you with info and insights you can use to make such discussions more productive! Naturally, all comments by, or references to, third parties represent their own views, and Lemonade assumes no responsibility for them. Coverage may not be available in all states. Please note that statements about coverages, policy management, claims processes, Giveback, and customer support apply to policies underwritten by Lemonade Insurance Company or Metromile Insurance Company, a Lemonade company, sold by Lemonade Insurance Agency, LLC.  The statements do not apply to policies underwritten by other carriers.