Understanding Kidney Disease in Dogs: Causes, Symptoms, and Treatment Options

Kidney disease in dogs ranges from sudden, often reversible acute kidney injury (AKI) to progressive, long-term chronic kidney disease (CKD). Early recognition, proper diagnosis and targeted care can make a major difference in your dog’s comfort and lifespan. 

The sections below explain causes, how the disease shows up, how vets diagnose it, current treatment approaches, monitoring and practical tips for pet parents. 

Acute versus chronic: what’s the difference?

Acute Kidney Injury (AKI) is a rapid loss of kidney function that may be caused by toxins (for example, antifreeze/ethylene glycol), certain medications (some NSAIDs, aminoglycoside antibiotics), infections, heatstroke, or decreased blood flow to the kidneys. AKI can be life-threatening but may be reversible with prompt treatment. 

Chronic Kidney Disease (CKD) is a progressive, irreversible loss of functional nephrons developing over weeks to years. Causes include prior severe kidney injury, infections, immune-mediated disease, congenital conditions, renal scarring from repeated injuries, or diseases such as kidney cancer. CKD is managed long-term to slow progression and preserve quality of life. 

Common Causes and Risk Factors

Several underlying factors can damage a dog’s kidneys gradually or very suddenly, and knowing these can help dog parents protect their pets better. Here’s a more detailed look at the most common causes and how they affect kidney health:

• Toxins

Substances like antifreeze (ethylene glycol), certain human medications, lilies and other toxic plants, and rodenticides can severely damage the kidneys within hours. Even small amounts of these toxins can destroy kidney tissue, making immediate veterinary attention critical if exposure is suspected.

• Infections and Inflammatory Diseases 

Bacterial infections such as leptospirosis or kidney infections (pyelonephritis) can inflame and injure the kidneys. Some immune-mediated conditions can also cause the body to attack its own kidney tissue, gradually reducing kidney function over time.

• Reduced Blood Flow or Shock 

Conditions that lead to sudden dehydration, severe vomiting or diarrhoea, heatstroke, or blood loss can drastically reduce blood flow to the kidneys. When the kidneys don’t receive enough oxygen and nutrients, the tissue can become damaged, leading to acute kidney injury.

• Congenital or Breed Predisposition and Age 

Some puppies are born with structural kidney abnormalities or genetic conditions that make the kidneys fail earlier in life. Additionally, older dogs naturally lose kidney efficiency with age. Certain breeds like Shih Tzus, English Cocker Spaniels, and Bull Terriers may have a higher risk of inherited kidney issues. 

Signs and Symptoms to Watch For

Early kidney disease often causes subtle signs. As function declines, you may notice:

• Increased thirst and more frequent urination (often the earliest signs). 

• Loss of appetite, weight loss, weakness, lethargy.

• Vomiting, nausea, bad breath (uremic odour), and dehydration.

• Changes in urine (blood, straining to urinate) and poor coat condition.

• In advanced CKD: anaemia, high blood pressure, and neurological signs. Prompt veterinary attention is essential for any sudden change. 

How Veterinarians Diagnose Kidney Disease

Diagnosing kidney disease requires a step-by-step approach that helps veterinarians understand how well the kidneys are functioning and what may be affecting them.

1. Blood Tests
   

• Serum creatinine and Blood Urea Nitrogen (BUN) are measured to assess how efficiently the kidneys filter waste from the bloodstream. 

• Symmetric dimethylarginine (SDMA) is included as an early detection marker because it can indicate kidney decline even before creatinine rises.

• Results are often repeated over time to confirm consistent trends rather than temporary fluctuations.
  

2. Urinalysis
   

• Urine specific gravity is checked to evaluate the kidneys’ ability to concentrate urine.

• The sediment is examined for crystals, cells, or bacteria that might indicate infection or underlying disease.

• The urine protein-to-creatinine ratio (UPC) is measured to detect proteinuria, which plays an important role in IRIS staging.
  

3. Imaging Tests
   

• Abdominal ultrasound helps identify structural issues, inflammation, congenital abnormalities, or chronic changes in the kidneys.

• X-rays may be used to detect stones, obstruction, or changes in kidney size or shape.
  

4. Additional Diagnostics
   

• Blood pressure measurement is essential, as high blood pressure is common in kidney disease and can further damage kidney tissue.

• A complete blood count helps detect anaemia, which often develops with chronic kidney disease.

• Electrolyte testing is performed to monitor potassium, phosphorus, and other values affected by reduced kidney function.

• Urine culture is recommended if infection is suspected, particularly in dogs with recurrent urinary symptoms or fever.
  

5. Rule-Out Evaluation
   

• Vets also assess whether non-kidney factors are causing abnormal results.

• For example, dehydration or recent illness can temporarily elevate creatinine, so clinical context and repeat testing help avoid misdiagnosis.

Treatment Approaches: Acute Versus Chronic Kidney Diseases

Acute kidney injury (AKI)

• Intravenous fluids to correct dehydration and restore renal perfusion (critical in many AKI cases). Fluid therapy is usually intensive and closely monitored.
  

• Remove the cause when possible (e.g., decontamination for some toxins, stop nephrotoxic drugs).
  

• Supportive care: Anti-nausea medication, gastroprotectants, electrolyte correction, and management of complications.
  

• In selected, severe cases, advanced therapies such as dialysis or continuous renal replacement may be considered at referral centres. 

Chronic kidney disease (CKD)

CKD is managed long-term with a combination of medical therapy, diet and monitoring:

• Dietary management: renal support diets lower phosphorus and often moderate protein while maintaining adequate calories; they also adjust sodium, potassium and acid-base balance. Diet changes can slow progression and improve well-being.
  

• Control phosphorus: dietary phosphorus restriction or phosphate binders when levels are high. Keeping phosphorus in target ranges is linked to better outcomes.
  

• Treat hypertension and proteinuria: ACE inhibitors or angiotensin receptor blockers can reduce protein loss through the kidneys; anti-hypertensive therapy is used when blood pressure is high.
  

• Manage clinical signs: antiemetics, appetite stimulants, potassium supplementation for hypokalemia, and treatment of anaemia when present. Omega-3 fatty acids may also have renal benefits.
  

• Address infections and obstruction: treat urinary tract infections with appropriate antibiotics and relieve urinary obstructions urgently.
  

• Fluid therapy for rehydration or intermittent subcutaneous fluids at home can improve hydration and comfort for some CKD dogs. 

Some Crucial Advice for Dog Parents

1. Act fast for abrupt signs: Sudden vomiting, collapse, reduced urination, or known toxin exposure require immediate veterinary care. Early intervention can be lifesaving.

2. Preventive care: Keep pets up to date on vaccinations, avoid accidental access to toxic substances (antifreeze, medicines), and use veterinary-approved flea, tick and parasite preventives.

3. Nutrition: Discuss dietary choices with your vet early; transitioning to a renal support diet is best done under supervision. 

4. Home monitoring: Track drinking, urination, appetite and weight; share these with your vet so they can adjust care promptly.

5. Work with your vet: Looking after your vet is a team effort; regular communication, lab monitoring, and sensible palliative measures are keys to a good quality of life.

When to Contact Your Veterinarian (Red Flags)

• Sudden decrease in urine production or no urine

• Persistent vomiting or severe diarrhoea

• Collapse, severe lethargy or seizures

• Known ingestion of toxin (antifreeze, certain human meds)

Kidney disease can feel overwhelming, but early veterinary care, the right diet, and steady home monitoring can greatly improve your dog’s comfort and quality of life. Small everyday choices - from feeding to hydration to creating a calm routine truly make a difference.

For any essentials you may need along the way, having a trusted, all-in-one pet destination makes the journey easier. You can always explore everything in one place online or visit your nearest HUFT store for convenient, thoughtful support as you care for your dog’s health.

Frequently Asked Questions 

What early signs should I watch for at home?

Increased thirst, frequent urination, reduced appetite, mild vomiting, weight loss, and low energy are common early indicators. Subtle changes like peeing at night or finishing the water bowl faster than usual can also be clues.

Can dehydration lead to kidney problems in dogs?

Yes. Severe dehydration from heatstroke, vomiting, diarrhoea, or inadequate water intake reduces blood flow to the kidneys, leading to acute injury.

What diet is recommended for dogs with kidney issues?

Kidney diets focus on controlled protein, reduced phosphorus, balanced sodium, higher moisture, and omega-3 fatty acids. These adjustments reduce kidney workload and help maintain comfort.

Can exercise help dogs with kidney disease?

Moderate, low-stress exercise is beneficial. However, overly intense activity can worsen dehydration. Short walks and calm play are best.