Kidney disease in cats: Types, symptoms, and treatments

There are a variety of kidney diseases in cats that affect kidney function. These conditions can vary in severity, prevalence, and how they impact a cat’s quality of life. If you have a cat, continue reading to discover:

• What types of kidney10 disease can cats have?
• What are the common symptoms of kidney disease in cats?
• How is renal disease diagnosed and treated in cats?

Many types of kidney diseases in cats have similar symptoms, and accurate diagnosis is required for effective treatment. Many conditions can lead to acute or chronic renal failure in cats. Treatment varies based on the type of kidney disease, its underlying cause, and how severe the kidney damage is.

Kidney disease is a broad term used to describe many conditions that affect kidney function in cats. These conditions can vary widely in prevalence, severity, underlying cause, and how they impact a cat’s life. Types of feline kidney disease include:

Chronic kidney disease

Chronic kidney disease (CKD) is the loss of renal function over time. The condition is also known as chronic renal failure, chronic kidney failure, chronic renal disease, or chronic renal insufficiency. CKD is a progressive illness and is very common, especially in older cats. CKD is irreversible and eventually fatal. With early diagnosis and proper disease management, progression of CKD may be slowed and quality of life can be maintained for some cats.

Kidney stones

Urine crystals can form in the kidneys or bladder as natural minerals separate and cluster together. Kidney and bladder stones form when these crystals clump together to form larger structures. Kidney stones, bladder stones, and crystals are excreted through the urine. Crystals and small stones may pass through the urine undetected, but large stones can block the urethra or ureters, causing a life-threatening urinary blockage. An untreated urinary blockage can quickly lead to acute kidney failure. Kidney stones are far less common than bladder stones and urinary crystals associated with feline lower urinary tract disease.

Bacterial infection of the kidneys

Bacteria can enter and multiply in the kidneys, leading to infection. Kidney infections most often occur when bacteria from a bladder infection travel up the ureters to the kidneys. Infections elsewhere in the body can spread to the kidneys through the bloodstream or produce byproducts that can damage the kidneys. Kidney infections can be serious and lead to life-threatening sepsis, which is a bacterial infection in the bloodstream, and kidney failure. However, they are uncommon in cats.

Acute kidney failure

Acute kidney failure, also known as acute kidney injury (AKI), acute kidney disease, or acute renal failure, is the sudden damage to kidney tissue that interferes with renal function. This type of kidney failure in cats can sometimes be treated, depending on the severity and underlying cause. “Rather than referring to a traumatic injury, acute kidney injury is used to describe sudden damage to the kidneys. This is different from chronic kidney disease, where the kidneys wear out over an extended period of time,” explains Dr. Jo Myers, a veterinarian on the Vetster platform. “However, acute kidney injuries can lead to chronic kidney failure if the cat survives and the kidney damage is great enough.” The degree of kidney injury can be mild to severe, and can also be fatal. AKI in cats has many possible causes, including:

• Urinary obstruction due to feline lower urinary tract disease
• Exposure to toxic plants, such as lilies
• Ibuprofen (NSAID) toxicosis
• Infections
• Some medications
• Heatstroke
• Lymphoma and other cancers
• Venomous snakebite
• Lead poisoning

Some medical conditions are also associated with acute kidney failure in cats, including:

• Diabetes mellitus
• Pancreatitis
• Fatty liver disease

Congenital kidney disease

Congenital kidney diseases are conditions present at birth that affect the kidneys. They include:

• Polycystic kidney disease
• Underdeveloped kidneys (kidney hypoplasia)
• Kidneys fail to develop (kidney agenesis)

Polycystic kidney disease is the most common congenital kidney disease in cats. Feline congenital renal diseases range in severity, prevalence, and how much they impact a cat’s life.

Kidney cancer

Cancerous tumors can develop on or within the kidneys, causing kidney cancer. There are various types of tumors that can affect the kidneys, and some cancers can spread to the kidneys from other parts of the body. Kidney cancer is rare in cats, and the prognosis is generally poor, even with treatment.

Healthy kidneys in cats are responsible for filtering waste from the body, creating urine, regulating hydration, blood pressure, and electrolyte balance, and producing the hormone responsible for blood cell production. As a result, when renal function is damaged, cats can have a wide variety of symptoms. Most kidney conditions share symptoms, such as:

• Increased water intake
• Excessive urination
• Straining to urinate
• Lethargy
• Vomiting
• Blood in the urine
• Lack of appetite
• Weight loss
• Bad breath
• Changes to normal behavior
• Pale gums

Increased thirst and urination are often the first signs of kidney disease in cats. Straining to urinate can be a sign of a urinary blockage due to bladder or kidney stones, which is a medical emergency. It can be difficult to see whether a cat is straining to urinate or straining due to constipation, especially if they are urinating in small amounts. It’s best to talk to a veterinarian when straining is observed, just to be safe. In addition, kidney diseases can develop secondarily or share symptoms with other health conditions. Talk to a vet any time your cat shows signs of illness or changes to their normal behavior. Cats who have developed kidney failure due to dangerous toxins or an underlying medical condition may have additional clinical signs.

After a physical exam, a vet may recommend diagnostic testing to help determine the underlying cause of the kidney disease and the extent of the kidney damage. Diagnostic tests may include:

• Urinalysis and urine culture
• Blood tests
• Diagnostic imaging such as X-rays or ultrasound
• Kidney biopsy

Initial urine tests and blood work may show evidence of kidney damage but not indicate the underlying cause or severity. Additional testing is often necessary to reach a definitive diagnosis.

Treatment options vary widely for different kidney diseases. A treatment plan for feline renal disease may include:

• Antibiotics
• Prescription renal diet
• Hospitalization
• Urinary catheterization
• Fluid therapy
• Flushing the urinary tract to remove stones or crystals
• Surgery, such as kidney transplants
• Other symptomatic treatments for nausea, appetite loss, and pain
• Kidney dialysis
• Chemo and radiation therapy
• Palliative care

Kidney conditions often cannot be reversed and require ongoing maintenance. Work with a veterinarian for long-term monitoring and treatment. A veterinarian may recommend offering a therapeutic diet to a cat with chronic kidney disease.

Dialysis and kidney transplants are used far less often in cats compared to humans and are rarely options to treat feline renal disease. Chemotherapy and radiation may not be curative, depending on the cancer type. Kidney cancer treatments in cats often aim to alleviate symptoms, improve quality of life, and extend time with owners.

It’s important for cat owners to avoid attempting to diagnose or treat their cat’s kidney or urinary issues at home. Doing so can be dangerous and delay proper treatment, allowing the condition to get worse.

It’s important to talk to a vet any time you notice physical or behavioral changes in your cat. Clinical signs can often be subtle and go unnoticed or be attributed to old age. However, chronic kidney failure is very common in senior cats, so symptoms should not be overlooked.

If a cat is straining to urinate or is unable to urinate, seek veterinary care right away, as this can be a sign of a life-threatening urinary blockage.

Diagnostic testing is needed for an accurate diagnosis of kidney disease, its underlying cause, and the severity of the damage. An accurate diagnosis is needed for effective treatment. If your cat is showing symptoms of kidney failure, or you are concerned about your cat’s risk for kidney failure, you can talk to a veterinary professional in a virtual vet appointment through the Vetster platform.

Can kidney disease be reversed in cats?

Some cases of acute kidney injury caused by toxin ingestion, medications, or traumatic injury may be reversed, depending on severity and response to treatment. However, chronic kidney disease and congenital renal diseases such as polycystic kidney disease cannot be reversed. Progression of disease may be slowed, and quality of life can often be maintained with appropriate treatment.

How long do cats live after being diagnosed with kidney failure?

Chronic kidney failure is ultimately fatal for cats. However, if it is caught early and responds well to treatment, the condition can be managed for several years after diagnosis. While kidney failure can be immediately life-threatening, cats with well-managed disease can maintain a good quality of life for months or even years.

How does a cat with kidney disease act?

Cats with kidney disease may be lethargic, drink more water than usual, and urinate frequently. Some cats may also vomit and show a decrease in appetite. Finally, some types of kidney disease may lead to straining in the litter box and vocalizing while trying to urinate.