Renal insufficiency in dogs

Kidney failure in dogs – causes, symptoms and treatment

Kidney failure is one of the most common conditions in older dogs and, if not diagnosed and treated promptly, can lead to serious health problems. The kidneys are vital organs that play a key role in the body's detoxification process. They filter waste products from the blood, regulate water balance, and produce hormones important for blood pressure regulation and red blood cell production. When kidney function is impaired, it can lead to a variety of symptoms and complications. In this article, you'll learn what kidney failure in dogs means, how to recognize it, and how you can help your dog.

What is kidney failure?

Renal insufficiency , or kidney failure , refers to the condition in which the kidneys lose their ability to filter waste products and excess water from the body. This can be either acute or chronic:

• Acute kidney failure occurs suddenly, often due to an injury or a serious illness such as infection, poisoning, or sudden fluid loss.

• Chronic renal failure develops over time and is the most common form of renal failure in older dogs. It is usually the result of long-term kidney failure and often leads to a gradual loss of kidney function.

Both forms of kidney failure can have serious effects on your dog's entire body, which is why early diagnosis and treatment are important.

Causes of kidney failure in dogs

There are a variety of possible causes of kidney failure in dogs. The most common are:

1. Chronic kidney disease (CKD)

Chronic kidney disease is one of the most common causes of kidney failure in older dogs. It can be caused by a number of factors, including:

• Hereditary diseases (especially in certain breeds such as Dobermans, Cocker Spaniels or Samoyeds)

• High blood pressure (hypertension), which can damage the kidneys

• Inflammation of the kidneys (nephritis)

• Diabetes mellitus , which can damage the kidneys

2. Acute kidney damage

Acute kidney damage can occur suddenly and often results from:

• Poisoning , e.g. from chocolate, onions, rat poison or certain medications such as non-steroidal anti-inflammatory drugs (NSAIDs).

• Heat stroke or sudden dehydration.

• Injuries caused by trauma or accidents that lead to internal bleeding and damage to the kidneys.

3 . Urinary tract infections

Chronic or recurrent urinary tract infections can spread to the kidneys and cause long-term kidney failure. In severe cases, pyelonephritis can lead to irreversible damage.

4. Kidney stones and tumors

Kidney stones, tumors, or cysts in the kidneys can block normal renal flow and lead to kidney failure. These can damage the kidney structure and impair function.

Symptoms of kidney failure in dogs

The symptoms of kidney failure are often gradual and develop over weeks to months, especially in chronic kidney failure. The most common signs include:

1. Increased thirst and frequent urination

Because the kidneys are no longer able to regulate fluids efficiently, affected dogs often drink larger amounts of water and also need to urinate more frequently. In advanced stages, however, reduced urine output may occur.

2. Weight loss and loss of appetite

Another common sign of kidney problems is unintentional weight loss , even though the dog is still eating. Appetite may decrease due to the accumulation of waste products in the body and the associated nausea.

3. Vomiting and diarrhea

The accumulation of toxins in the body (particularly in the case of progressive chronic renal failure ) often leads to vomiting and, in some cases, diarrhea .

4. Fatigue and weakness

A dog with kidney failure may appear weak and tired because the body has difficulty eliminating waste products and maintaining fluid balance.

5. Dehydration

Due to frequent urination and a reduced ability to retain fluids, the dog can quickly become dehydrated. A dry mouth, drooping ears, and slowed skin elasticity are signs of dehydration.

6. Odor in the breath

A typical symptom of advanced kidney failure is the so-called uremic odor on your dog's breath, reminiscent of ammonia. This is caused by the increase in urea and other waste products in the blood.

7. Blood in the urine

In some cases, blood may appear in the urine , indicating possible inflammation, infection, or kidney stones.

Diagnosis of renal insufficiency

To diagnose kidney failure in your dog, your veterinarian will usually perform a combination of the following tests:

• Blood test : This involves measuring urea and creatinine levels to check kidney function. An elevated creatinine level often indicates impaired kidney function.

• Urine tests : A urine test can show protein loss and other abnormalities that indicate kidney damage.

• Ultrasound examination : Using an ultrasound device, the veterinarian can check the structure of the kidneys and detect any changes such as stones, tumors or cysts.

• X-rays : X-rays can help rule out other possible causes of symptoms, such as tumors.

Treatment of renal failure in dogs

Treatment for kidney failure depends on the cause, severity, and stage of the disease. The goal of treatment is to improve your dog's quality of life and maintain kidney function for as long as possible.

1. Drug treatment

• Antihypertensive medication : Since high blood pressure can damage the kidneys, your veterinarian may prescribe antihypertensive medication.

• Phosphate binders : These medications help lower phosphate levels in the blood, as high phosphate levels can further damage the kidneys.

• Antibiotics : If a urinary tract infection is the cause of kidney failure, antibiotics may be necessary.

2. Diet and hydration

Nutrition plays a central role in the treatment of kidney failure. There are special kidney diets that:

• Contain less phosphorus and protein to avoid placing additional strain on the kidneys.

• Provide increased amounts of omega-3 fatty acids to support the kidneys.

Additionally, your dog may need fluid replacement , either orally or via IV fluids , to prevent dehydration.

3. Herbs and dietary supplements

Some herbs and supplements can support kidney function, such as goldenrod, nettle , and birch leaves. These herbs contain pressure-free herbs that help our kidneys function. However, these should only be used under the guidance of a veterinarian, as they are not suitable as a sole therapy.

4. Dialysis or kidney transplantation

In very severe cases of acute kidney failure, dialysis may be necessary to remove toxic waste products from the blood. A kidney transplant is an option in a few cases, especially if one kidney fails completely.

What can you do?

Kidney failure is a serious condition that can be managed effectively with early diagnosis and appropriate treatment. Pay attention to the symptoms that indicate kidney problems and consult your veterinarian if you have any concerns. You can help your dog with a healthy diet, regular veterinary checkups, and the right therapy.

Source: Martina Hemm March 2025