Kidney Disease in Dogs: Symptoms, Causes & Treatment Guide

Kidney disease in dogs is a condition where the kidneys fail to function properly, affecting their ability to filter toxins, regulate blood pressure, and maintain important metabolic balances. It can present as either an acute or chronic condition, with symptoms varying in severity and progression. This comprehensive guide explores signs, causes, diagnosis, treatment, and prevention of canine kidney disease, providing practical advice for responsible dog owners.

A Review of Normal Kidney Function

The kidneys are vital paired organs situated in the abdominal cavity that perform essential regulatory tasks. They filter waste products such as urea and ammonia from the blood, directing these through ureters to the urinary bladder for excretion. Beyond waste removal, kidneys produce key hormones like erythropoietin, which stimulates red blood cell production. They also regulate blood pressure by managing salt and water levels and maintain electrolyte and acid-base balance. Each kidney consists of many nephrons, microscopic filtering units that concentrate urine and control bodily chemistry. When kidney disease disrupts this function, symptoms begin to appear.

Understanding Kidney Disease Terminology

The terminology surrounding kidney issues can sometimes be confusing. 'Renal' simply means 'related to the kidney'. 'Renal disease' indicates kidney abnormalities, while 'renal failure' means kidney function is significantly decreased. Renal failure typically occurs after about 75% of the nephrons in both kidneys stop functioning. This results in the kidneys being unable to concentrate urine and a buildup of nitrogenous waste in the bloodstream, known as azotaemia.

Chronic kidney disease (CKD) is the most common kidney disorder in dogs and is defined as the ongoing presence of functional or structural kidney abnormalities. It involves irreversible nephron loss over at least three months, leading to progressive kidney failure. Conversely, acute renal disease develops suddenly and often severely, sometimes causing acute renal failure.

Recognising the Symptoms of Kidney Disease in Dogs

Symptoms for chronic kidney disease tend to develop slowly over weeks or months and may include:

• Increased thirst and urination, sometimes resulting in accidents indoors
• Loss of appetite and weight loss
• Vomiting and nausea
• Lethargy and weakness
• Bad breath
• Poor coat condition

In acute kidney failure, symptoms appear suddenly and are more severe, including all of the above plus:

• Weakness or collapse
• Depression or disorientation
• Abdominal pain
• Seizures
• Pale gums from anaemia
• Vision loss due to high blood pressure

Common Causes of Kidney Disease in Dogs

Chronic kidney disease often has unclear origins but potential causes can include:

• Inherited conditions, particularly in certain purebred dogs
• Infections such as leptospirosis
• Exposure to toxins like antifreeze or certain medications
• Immune-mediated diseases
• Kidney tumours or obstructions

Acute renal failure often results from:

• Severe dehydration or reduced blood flow to the kidneys (for example, adverse reactions to anaesthesia)
• Accidental ingestion of toxic substances

Diagnosing Kidney Disease

Your vet will begin diagnosis with a detailed history and physical examination. Blood and urine tests are essential to confirm kidney disease and assess severity. Blood pressure measurement is common, as abnormalities may be a cause or consequence. Imaging such as ultrasound or X-rays may be used if underlying issues like obstructions are suspected. A kidney biopsy is occasionally performed but carries some risk and is not routinely necessary.

Treatment Approaches for Kidney Disease

Treatment depends on the condition's type and severity. While chronic kidney disease is irreversible, management can improve quality of life and slow progression. Key treatments include:

• Treating underlying causes where identified, such as antibiotics for infections
• Dietary management including reduced phosphate and specially formulated kidney diets rich in omega-3 fatty acids to support kidney health
• ACE inhibitors to improve kidney blood flow and control blood pressure
• IV fluid therapy and symptom management for nausea and vomiting, especially in acute cases

Dogs with acute renal failure require intensive monitoring, electrolyte management, and supportive care. Prognosis varies widely based on cause and damage extent, so close collaboration with your vet is crucial.

Preventing Kidney Disease in Dogs

Some kidney diseases are unavoidable, but risk can be minimised by:

• Avoiding feeding grapes, raisins, and access to antifreeze, which are toxic to dogs
• Keeping vaccinations up to date, especially for leptospirosis
• Regular veterinary check-ups for older dogs, ideally every six months, to screen for kidney function
• Monitoring water intake monthly, noting increases which may signal disease (normal is less than 60ml/kg bodyweight per day, increasing with dry food diet or hot weather)
• Watching closely for symptoms and promptly consulting your vet if concerns arise

Frequently Asked Question: How can I tell if my dog has kidney disease?

Quick Answer: Key signs include increased thirst and urination, decreased appetite, vomiting, weight loss, and lethargy. Early symptoms can be subtle, so regular vet checks are important.

Kidney disease often progresses slowly, and dogs may not show obvious signs until more than 75% of kidney function is lost. Monitoring drinking habits and urine frequency at home can help detect changes early. A vet can perform blood and urine tests to confirm diagnosis and initiate appropriate management to slow progression and maintain quality of life.

Conclusion

Kidney disease in dogs is a common but complex condition requiring early recognition, veterinary diagnosis, and ongoing management to optimise outcomes. Responsible pet owners who understand the symptoms and risk factors can work closely with their vets to provide supportive care, potentially extending life and comfort for their beloved companions.