Kidney disease in dogs: Signs, causes and treatment

While we tend to associate the diagnosis of kidney disease more with our feline friends, it’s important to be aware that this condition can affect our canine companions too.

Here’s more information on kidney disease in dogs, including potential causes, common symptoms, and how vets can help with the diagnosis and treatment of canine kidney problems.

Understanding kidney disease in dogs

Overall, the kidneys have three essential roles in the maintenance of health:

• Filtering the blood to create urine, which allows the body to:
  • Clear waste products from the body
  • Maintain appropriate hydration levels through conservation or elimination of water
  • Maintain blood chemistry (including electrolyte/salt levels and pH balance) within a healthy narrow range
• Helping to regulate blood pressure
• Producing a hormone that stimulates bone marrow to make more red blood cells (which carry oxygen)

CKD (chronic kidney disease) involves a progressive and irreversible loss of kidney function over a period of months to years.

The kidneys can also be injured suddenly by a number of potential causes, such as toxins, infections, trauma, or other significant health problems causing generalised body-wide inflammation or compromised blood flow. This is known as AKI (acute kidney injury).

Common symptoms and warning signs

As the kidneys have a significant reserve capacity, dogs in the earlier stages of CKD will often show no obvious outward signs, and will only develop symptoms of unwellness when they lose over 2/3 of their overall kidney function. AKI, however, tends to be associated with sudden and more significant symptoms of unwellness, either due to the kidney injury itself or from an underlying issue that is triggering it (such as severe pancreatitis).

Symptoms of early CKD in dogs can be vague, and include:

• Weight loss
• Reduced/variable appetite
• Reduced activity
• Increased thirst and urination (which may lead to indoor wee accidents at night from a fuller bladder)

As CKD progresses and more kidney function is lost, affected dogs may develop additional signs including:

• Vomiting and/or diarrhoea
• Muscle wastage
• Pale gums due to anaemia
• Bad breath

Dogs (and cats) with AKI do not usually have the same history of gradual unwellness, instead often showing a more obvious onset of illness symptoms, such as:

• Vomiting and/or diarrhoea
• A loss of appetite
• Lethargy and/or weakness
• Changes in urine production

They may also have additional symptoms related to another illness (if this is the underlying cause of their AKI), such as tummy pain or blood-tinged vomiting and diarrhoea.

Around 60-80% of dogs with kidney disease will develop secondary hypertension (high blood pressure), which can cause changes to their eyes, brain and heart, and also worsen their kidney damage.

Causes and risk factors

CKD is most common in older dogs (10+ years in smaller dogs, 7+ years in larger breeds), although it can occur in younger dogs due to congenital kidney conditions such as renal dysplasia. In many affected pets, the exact trigger for CKD is unknown, because the condition is often diagnosed in the later stages of a gradually progressive disease process that has been going on for months to years.

AKI is known to occur secondary to:

• Toxins such as grapes/sultanas, snake bites, or antifreeze
• Adverse effects or overdoses of certain medications (such as NSAIDS)
• Other severe illnesses that cause significant inflammation or reduced blood flow around the body, such as pancreatitis, heatstroke, or heart failure
• Bacterial infections such as leptospirosis
• Trauma to the kidneys
• Urinary tract mineralisations (stones) that block urine flow

Diagnosis of kidney disease in dogs

Kidney function can be assessed with blood tests that check the levels of three waste products normally filtered by the kidneys into urine:

• blood urea nitrogen (BUN or urea)
• creatinine
• symmetric dimethylarginine (SDMA)

Ideally, the levels of these blood parameters should be interpreted alongside urine tests to check the dog’s urine concentration, as elevated levels of these parameters combined with inappropriately dilute urine more strongly supports kidney disease, which could be either CKD or AKI.

Differentiating CKD (progressive and irreversible) from AKI (which pets can potentially partially or completely recover from with timely treatment) is key for the most effective management, but can be difficult and depends on factors such as:

• The duration and progression of the dog’s kidney parameter elevations
• The duration of the dog’s symptoms
• If the dog has any clear history or evidence supporting a recent illness or injury that could have damaged their kidneys – this may require additional diagnostic tests such as general blood tests, abdominal ultrasound or infectious disease tests to investigate

CKD and AKI in dogs (and cats) can be officially staged/graded according to IRIS guidelines, which help vets to make the most appropriate recommendations for ongoing treatment, monitoring and management of the pet’s condition.

Once kidney disease is diagnosed, the veterinarian will also often recommend monitoring of the pet’s blood pressure, due to the risk of secondary hypertension.

Treatment of kidney disease in dogs

Unfortunately, dogs with CKD can’t be cured, but they can be managed to help them feel well for longer and slow their rate of kidney deterioration. This can be done through:

• Supporting kidney function via:
  • Transitioning the dog to a prescription kidney support diet containing reduced levels of protein, phosphorous and salt
  • Ensuring the dog is always well hydrated, and administering supplementary fluids as required during periods of unwellness
• Treating any complications that arise from the kidneys not working as well by regularly monitoring for and treating issues such as:
  • Urinary tract infections
  • High blood pressure
  • Excessive urine protein loss
  • Increased levels of phosphorus or potassium in the blood
• Helping the dog to feel as well as possible by managing any symptoms such as nausea or gut irritation that can develop in more advanced or severe kidney disease patients
• Minimising any factors that can hasten kidney deterioration, such as the avoidance or judicious usage of drugs that can potentially have adverse effects on kidney health.

With the right supportive care, however, kidneys affected by AKI can recover partial or complete function again, depending on the level of injury that occurred. Overall, treatment of AKI involves:

• Investigating for and treating any underlying cause
• Maintaining normal hydration and blood electrolyte balance, usually requiring carefully tailored intravenous fluid therapy (a drip) in the initial stages
• Serial monitoring of the pet’s kidney health, hydration and blood chemistry parameters
• Managing any secondary complications of unwellness symptoms, such as:
  • Nausea
  • Gut irritation
  • Tummy pain

In some cases, dogs with severe AKI (e.g. kidney failure) may require haemodialysis (a specialist service where blood toxins are removed via an external filtering process, so that the dog’s kidneys can have time to recover), but this is not financially possible for many owners.

Supporting your dog’s health

The best way to monitor your doggo’s overall health is through regular veterinary health assessments. It’s recommended to book your pet for a general health check:

• At least every 12 months for healthy small breed dogs up to 10 years of age and healthy large breed dogs up to 7 years of age
• At least every 6 months for older dogs
• Every 3-6 months for dogs diagnosed with CKD or another chronic health condition
• Any time your pet shows symptoms of unwellness

As part of your dog’s assessment, your veterinarian may recommend diagnostic tests such as blood tests, urine tests, and blood pressure measurement.

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1 Oct 2026