Kidney Disease in Dogs: Everything you need to know

Kidney disease, including kidney failure, can occur as a result of numerous conditions in dogs. Clinical signs such as excessive urination and thirst, weight loss, and a picky appetite are common and can easily be attributed to old age. However, pet parents need to be aware of the signs of chronic kidney disease so they can help their senior dogs. Read on to discover:

• What conditions can affect a dog’s kidneys?
• What are the common symptoms of kidney disease in dogs?
• How is canine kidney disease diagnosed and treated?
• I think my dog has chronic kidney failure. What should I do?

Chronic kidney disease is a common kidney condition in dogs, especially in seniors. Signs can be very subtle until more than 65 percent of kidney function is lost. An accurate diagnosis and treatment from a veterinarian are needed to maintain an affected dog’s quality of life.

Kidney disease refers to several conditions that result in a loss of kidney function. The kidneys are responsible for many vital processes, including:

• Filtering waste from the body
• Creating urine
• Regulating hydration and water conservation
• Maintaining electrolyte balance
• Regulating blood pressure
• Producing the hormone that stimulates red blood cell production

Kidney damage has widespread effects on the body. Waste builds up in the body, dogs can become dehydrated and have electrolyte imbalances, and their red blood cell production drops. The kidneys have limited ability to repair themselves when damaged. There are multiple conditions that can negatively affect the kidneys, including:

Chronic kidney disease (CKD)

CKD, also known as renal failure, chronic kidney failure, or chronic renal disease, describes a gradual decrease in kidney function over time. CKD is common in senior dogs. Affected dogs often have few to no symptoms until 65 to 75 percent of their kidney function is lost. Chronic kidney disease cannot be reversed and may eventually be fatal. If detected and treated early, the condition can be well managed for a longer period of time and its progression can sometimes be slowed.

Bacterial infections

Harmful bacteria can affect the kidneys in two ways:

• When bacteria enter and establish in the kidneys
• When the kidneys are damaged by immune complexes formed by infection somewhere else in the body

Bacterial kidney infections (pyelonephritis) most often occur secondary to untreated urinary tract infections. Disease-causing bacteria that have established in the bladder travel up the urinary tract to the kidneys, where they multiply and cause symptoms. Bacterial kidney infections can also occur as a result of skin or respiratory infections. Kidney infections are uncommon in dogs. Symptoms of kidney infections often start out acutely with severe symptoms, but dogs who survive may have permanent damage causing chronic kidney disease. Leptospirosis is one example of a bacterial infection that creates immune complexes that damage the kidneys. Leptospirosis spreads through contact with the urine of infected wildlife, so risk of exposure varies based on location and a dog’s lifestyle. Vaccination against leptospirosis is available, and a consultation with a veterinarian on Vetster can help you assess the risks and benefits of vaccinating your dog.

While canine Lyme disease is characterized by joint pain, lethargy, and appetite loss, a small number of infected dogs develop serious kidney disease. Symptoms of Lyme nephritis include severe lethargy, appetite loss, vomiting, and diarrhea. As with leptospirosis, the acute kidney injury caused by the bacteria that cause Lyme disease can be fatal or leave surviving dogs with permanent damage. Lyme disease is more prevalent in some areas, and vaccination is available.

Kidney stones

Crystals and kidney stones form when minerals found in urine clump together. Urinary stones are common in dogs, and they usually form in the bladder. Stones in the kidneys are less common. Some small stones or crystals may pass without causing obvious symptoms, while others can cause severe complications. The severity of kidney stones varies depending on the size and location of the stone. Stones have the potential to block the urinary tract, which is a medical emergency and can quickly lead to acute kidney failure. Male dogs and small breeds are most at risk for urinary blockages from stones.

Acute kidney failure

Acute kidney failure, also called acute kidney injury (AKI), acute renal failure, or acute kidney disease, is the sudden loss of kidney function. Acute kidney disease most often occurs due to an infection, such as leptospirosis or Lyme disease, urinary obstruction, or ingestion of a toxin. Household toxins that can cause acute kidney failure include:

• NSAIDs (ibuprofen)
• Grapes and raisins
• Antifreeze

Severity and prognosis can vary dramatically between cases. Sometimes dogs can recover from acute kidney failure, depending on the severity of the damage and how long it takes to get veterinary care. The majority of acute kidney failure cases are emergencies.

Renal cancer

Cancer and tumors can form on or within the kidneys. Cancer somewhere else in the body can also spread to the kidneys. Tumors can be malignant or benign, but even noncancerous tumors can damage kidney tissue. Cancer in the kidneys may be aggressive and difficult to treat. For most renal tumors, surgery to remove the tumor and affected kidney is the primary treatment, but this may not be feasible if both kidneys are involved. Prognosis varies significantly; malignant tumors or those that have spread generally have a poor outlook, while benign tumors or nephroblastomas, when surgically removed, are associated with better chances for a cure or long-term survival.

Congenital kidney disease

There are multiple kidney conditions that are congenital or can be inherited. They include:

• Renal agenesis
• Renal dysplasia
• Polycystic kidneys
• Renal amyloidosis
• Basement membrane disorder
• Fanconi syndrome

The severity varies between conditions and how they affect overall kidney function. Congenital kidney disorders are very rare in dogs. In addition to common symptoms of kidney disease, dogs with congenital kidney disease may have stunted growth and poor hair quality. These symptoms may be present when a puppy is born or they may develop as the dog grows older.

Clinical signs can vary between kidney conditions, but many share common symptoms resulting from decreased kidney function. Warning signs of kidney failure in dogs include:

• Increased thirst
• Excessive urination
• Bloody urine
• Lethargy
• Straining to urinate
• Sudden lack of urination
• Bad breath
• Finicky or poor appetite
• Weight loss
• Vomiting
• Pale gums

Increased thirst and excessive urination are often the first warning signs of kidney disease in dogs.

Is kidney disease an emergency?

Unproductive straining to urinate or being unable to urinate is a medical emergency that needs veterinary care right away. It can be challenging to differentiate between unproductive straining and urinating very small amounts, or to discern straining to urinate from straining due to constipation. Therefore, whenever you notice concerning symptoms in your dog, it's advisable to consult a veterinarian. Erring on the side of caution is crucial when dealing with potential emergencies.

Acute kidney disease due to toxins, infection, or urinary obstruction usually present suddenly as emergencies. Chronic kidney disease is a slow-progressing disease and not an emergency. However, dogs with chronic renal failure may show emergency symptoms that require treatment or hospitalization.

After a thorough physical exam and discussing the dog’s presenting symptoms with their owner, a veterinarian will likely recommend diagnostic tests. Testing helps a veterinarian evaluate the extent of kidney damage and visualize problems in the kidneys. Diagnostic tests may include:

• Urinalysis and urine culture
• Blood tests
• Infectious disease testing
• Imaging such as X-rays or ultrasounds
• Kidney biopsy

Crystals, stones, and bacteria can be seen in a urinalysis or in a urine culture. Routine blood work measures levels of waste products that healthy kidneys normally filter out of the blood. Imaging can show tumors, swelling, or other kidney abnormalities. In some cases, kidney biopsies may be recommended. Additional testing may be recommended if an underlying health condition is suspected of causing kidney damage. A definitive diagnosis is needed in order to provide proper treatment.

Is my dog at risk for kidney disease?

Some dogs are more likely to develop kidney disease than others. Potential risk factors include:

• Old age
• Obesity
• Breed
• Certain underlying health conditions
• Previous urinary or kidney conditions

Senior dogs are the most likely to develop chronic kidney disease, especially if they have diabetes mellitus or other health conditions that can negatively affect the kidneys. Some evidence suggests that obesity may affect kidney function, and those changes may be reversible with weight loss. Some dog breeds are more susceptible to certain types of kidney disease. Finally, some dogs who have had previous urinary or kidney conditions are more likely to have recurrences or develop others.

An effective treatment plan varies depending on the type of kidney problem your dog is diagnosed with. Treatments may include:

• Antibiotics for bacterial infections
• Fluid therapy
• Flushing stones from the urinary tract
• Dietary modification
• Surgery
• Toxicity treatment
• Other symptomatic care
• Palliative care
• Chemo and radiation therapy

Kidney dialysis and kidney transplants are used far less in dogs than in people and aren’t often practical or available. Chemotherapy and radiation are usually not meant to be curative in dogs and are instead used to alleviate symptoms and extend quality time with owners. Some dogs with chronic kidney disease may benefit from at-home medications and a special diet. Frequent veterinary visits for monitoring are usually recommended. As symptoms of chronic kidney failure progress, symptomatic treatments may change to improve quality of life. Symptomatic care may include:

• Medications for nausea and vomiting
• Appetite stimulants
• Fluid therapy
• Medications to stimulate red blood cell production

Prescription diets are available for dogs in renal failure. These special diets typically have reduced levels of sodium, protein, and minerals that may put stress on damaged kidneys. Talk to a veterinarian before switching to a new food.

“Treatment for many types of kidney disease focuses on managing the underlying cause before it can lead to more damage,” explains Dr. Jo Myers, a veterinarian on the Vetster platform. “The goal with chronic kidney disease is to increase quality of life by alleviating symptoms.”

How can I help my dog with chronic kidney disease?

Working closely with a veterinarian and following their instructions are necessary to manage chronic kidney disease in dogs. Routine checkups with a vet, therapeutic diets, and keeping a close eye on symptoms at home are some of the best things owners can do to help their dogs with kidney disease. Treatment plans are individualized and may change throughout a dog’s journey with the disease.

Talk to a veterinarian any time you notice changes in your dog’s physical health or behavior. It’s important for dog owners not to write off symptoms as “old age.” Decreased appetite, frequent vomiting, and excessive thirst and urination are often the first signs of an issue with the kidneys. Other health conditions, such as diabetes, can have similar symptoms, so diagnostic testing is necessary. If you have questions about your dog’s health or need advice on your dog’s chronic kidney disease, you can talk to an online vet through the Vetster platform.

How do dogs act when their kidneys are failing?

Early signs of kidney failure may be subtle and easy to overlook. Dogs in renal failure often drink and urinate more than normal. Picky eating habits, frequent vomiting, and lethargy can also occur with chronic kidney failure in dogs.

How long can a dog live with kidney failure?

The life expectancy of a dog with chronic renal disease varies depending on the severity of the damage, how quickly it’s progressing, and how well a dog is responding to treatment. Kidney failure in dogs can be managed for years or be immediately life-threatening.

What is the treatment for a dog with kidney disease?

Treatment options for kidney disease vary based on the underlying cause of the kidney issues. Possible treatments may include antibiotics for infection, fluid therapy, surgery, flushing stones from the urinary tract, and decontamination for toxin ingestion. Symptomatic treatments may become more aggressive in dogs with chronic kidney failure as their symptoms advance.

How quickly does kidney disease progress in dogs?

The speed at which kidney disease progresses in dogs is highly variable depending on the situation. Some dogs respond to treatment better than others, and underlying causes of kidney failure can vary in severity. It’s best to get wellness checks regularly, including blood work, and to talk with a vet about your dog’s kidney disease progression.

Are dogs with kidney disease in pain?

Some symptoms of kidney disease in dogs can be painful or unpleasant, such as lethargy, nausea, and vomiting. Long-term management of chronic kidney disease involves managing symptoms to improve quality of life.