By: Trupanion Staff / Updated June 26, 2021

As with humans, dogs rely on their kidneys to filter waste from their systems. These important organs work every day to cleanse the blood and assist with the removal unnecessary or even harmful substances from the body. When your dog's kidneys malfunction and are not performing as they should, your pet can be diagnosed with kidney failure.

In order to properly understand the risks and your pet's options for treatment, it's important to have an honest discussion with your dog's veterinarian. In the meantime, this guide can help shed some light on what happens in canine kidney failure and the different outcomes that can result.

What is kidney failure in dogs?

Kidney failure is defined by the kidneys' inability to effectively remove waste from blood. This waste builds up resulting in uremia and symptoms of kidney failure. Kidney failure can occur suddenly or gradually over time.

• Acute kidney failure: Acute kidney failure has a sudden onset. If diagnosed quickly and treated aggressively it is potentially reversible.
• Chronic kidney failure: Chronic kidney failure is the slow decline in the ability of the kidneys to eliminate waste from a dog’s body. The condition is incurable, but it can be managed with treatment.  This is more common than acute kidney failure.

Causes of canine kidney failure

• Ethylene glycol. Found in most antifreeze, prognosis is poor unless treated promptly after ingestion.
• Ureteral obstruction. Most commonly caused by a urolith (urinary stone) that results in restriction of urine flow.
• Lyme disease. This disease is carried by ticks and can result in chronic kidney failure for dogs.
• Heart conditions. These conditions can reduce blood flow to the kidneys, which results in failure.
• Hereditary and congenital conditions. Your vet will warn you if a condition your dog has been diagnosed with has the potential to cause kidney failure. You can then be aware of the symptoms should they develop.
• Aging. Sometimes, chronic kidney failure is idiopathic, and may be part of the natural aging process.

Signs of kidney failure in dogs

If you notice any of the signs of canine kidney failure listed below, schedule an appointment with your dog's veterinarian as soon as possible. While kidney failure is a progressive condition, fast intervention and treatment is key to survival.

Increased thirst

You will usually see your dog drinking more, or notice you are having to refill their water bowl more frequently.

Increased urination and/or 'accidents'

It might be worth keeping a note of how often you have to let your dog out to urinate. If this seems excessive, it’s a cause for concern. If your older, house-trained dog is suddenly having accidents in the house, kidney problems may be to blame.

Decreased urination

Yes, kidney problems can also lead to less urination than usual. If you notice this symptom, then your dog likely needs to see a vet as an emergency—the inability to urinate is very serious indeed.

Lethargy

Lethargy in and of itself is concerning, but in conjunction with the above, could be indicative of kidney issues.

Bad breath

Among other things this could be indicative of kidney issues. Breath associated with kidney failure can smell like ammonia, must, or sweat. Some have also likened it to a fishy scent.

Decreased appetite

When a dog’s kidneys fail, toxins such as ammonia and nitrogen can build up in their bodies. This, in turn, can cause nausea, vomiting, and/or a decreased appetite. This condition is known as uremia, and it is directly related to kidney failure.

Other uremia symptoms

Your dog may not be able to tell you how they feel, but it's time to call the vet if you notice signs like unexplained weight loss, diarrhea, and weakness.

How is kidney failure in dogs treated?

Acute kidney failure treatment includes addressing the underlying cause, if known. For example, antibiotics are used for an infection or specific antidotes may be available in cases of accidental poisoning. The kidneys may be supported using dialysis, which helps to remove toxins from the blood. Without treatment, acute kidney failure is fatal.