Sudden Kidney Failure in Cats. What You Need To Know


Kidney failure in cats, also known as renal failure, occurs when a cat’s kidneys become damaged and are no longer able to filter waste products out of the blood or perform other kidney functions. This results in a buildup of toxins in the blood which can cause a number of serious health issues. Kidney failure can be acute or chronic. Acute renal failure comes on suddenly, over a period of days or weeks, usually caused by a toxicity, infection or obstruction. Chronic renal failure progresses slowly over months to years. It is most often age-related as the kidneys naturally lose function as a cat ages. Both acute and chronic kidney failure are serious and can be fatal if left untreated, however chronic kidney failure is the most common form seen in cats.


Kidney failure in cats can either be acute or chronic. Acute kidney failure happens suddenly, over a period of days or weeks. Chronic kidney failure is a slower process that develops over months or years.

Some underlying diseases that can lead to kidney failure in cats include:

  • Kidney stones
  • Kidney inflammation
  • Kidney infection
  • Kidney cancer
  • Polycystic kidney disease

Toxins like antifreeze or lilies can cause acute kidney failure in cats. Infections, like feline leukemia virus or FIV, can also damage the kidneys over time. Kidney failure is more common in older cats as the organs wear out.


There are several common symptoms of kidney failure in cats that owners should watch out for. These include:

Increased thirst and urination

Cats with kidney failure will start drinking more water and urinating more frequently as their kidneys struggle to concentrate urine. This symptom is often one of the first signs of kidney problems. [1]

Weight loss

Kidney failure can lead to poor appetite, nausea, and metabolic changes that make it difficult for cats to maintain their body weight. Severe weight loss may occur over time. [2]

Poor appetite

Cats with kidney disease frequently have reduced appetites and lose interest in food as they start to feel unwell. This contributes to weight loss. [3]


The buildup of toxins in kidney failure creates nausea, which can lead cats to vomit frequently. Vomit may contain blood or appear brown in color. [2]

Bad breath

The ulcers, nausea, and oral inflammation associated with kidney disease can cause an ammonia-like odor on a cat’s breath. This symptom is sometimes called uremic breath. [3]





There are a few different ways vets diagnose kidney disease in cats:

The vet will start with a full physical exam and medical history. They will check for signs like weight loss, increased thirst and urination, poor coat quality, and oral ulcers. The physical exam allows the vet to feel for enlarged kidneys. Looking at the full history helps identify any past issues or potential causes.

Blood and urine tests are critical for diagnosing kidney issues. The vet will look for increased BUN (blood urea nitrogen), creatinine, and phosphorus levels in the blood. Elevated levels indicate the kidneys are not properly filtering waste products. A urine test checks for low urine concentration and protein loss. These are signs the kidneys are not functioning normally. 1

Imaging tests like x-rays, ultrasound, or CT scans provide visuals of the kidneys. They can reveal issues like small, irregular kidneys or kidney stones. These tests also check for masses, scar tissue, or other abnormalities.


There are several components to treating kidney failure in cats:

Hospitalization and Fluid Therapy

Cats with acute kidney injury or chronic kidney disease may need to be hospitalized for initial diagnosis, stabilization, and treatment. This often involves administration of intravenous fluids to rehydrate the cat and flush toxins from the body (VCA Animal Hospitals).


Certain medications may be prescribed to help manage kidney disease and related conditions like anemia, high blood pressure, vomiting, and inappetance. Common medications include anti-nausea drugs, phosphate binders, antihypertensives, erythropoietin, and antacids.

Dietary Changes

Vets often recommend a special veterinary kidney diet that is low in phosphorus and protein but still provides good nutrition. This helps reduce strain on the kidneys (South Wilton Veterinary Group).

Regular Vet Visits and Lab Work

Ongoing vet visits and lab work (blood and urine tests) are crucial for monitoring the cat’s kidney values and adjusting treatment as needed. Checking blood pressure is also important.


The prognosis for kidney failure in cats depends significantly on the underlying cause. Chronic kidney failure is unfortunately incurable and progressive, so the prognosis is generally poor long-term. However, with proper management like dietary changes, fluids, and medication, cats with chronic kidney disease can live for months or even years before the disease becomes debilitating.

For acute kidney failure, the prognosis is more optimistic if the underlying cause can be treated promptly. With aggressive therapy like hospitalization, IV fluids, medication, and supportive care, many cats can recover normal or near-normal kidney function. However, the prognosis declines the longer acute kidney injury goes unchecked and if irreversible damage occurs.

According to one source, most cats with acute kidney failure will stabilize with treatment, and around 67% may recover normal kidney function if treated within 48 hours. But the prognosis drops to about 45% if treatment is delayed 4-7 days. Sadly, some cats with severe acute kidney injury may not recover at all despite intensive care [1].


There are several ways cat owners can help prevent kidney disease in their feline companions:

Get annual veterinary exams to monitor your cat’s kidney function and overall health. Blood and urine tests can detect early signs of kidney issues.

Practice good dental care by regularly brushing your cat’s teeth or having professional cleanings done. Dental disease can lead to kidney infections.

Avoid exposing your cat to toxins like antifreeze, chemicals, certain medications, lilies, raisins, grapes, and xylitol. Keep trash and chemicals properly disposed of and out of your cat’s reach.

Encourage water intake by providing fresh, clean water bowls around the house, feeding wet food, using cat fountains, and adding water to dry food. Increased hydration supports kidney health.

Regular vet visits, dental care, avoiding toxins, and encouraging hydration can all help reduce your cat’s chances of developing kidney disease.

Living with Kidney Failure

Caring for a cat with kidney failure involves following your veterinarian’s recommendations for treatment while also providing supportive care at home. Monitoring your cat closely and making adjustments is key to their quality of life.

According to the VCA, following your vet’s prescribed “dietary modifications, medications, hydration therapy, and routine monitoring” is important for managing the disease and slowing its progression ( This can involve feeding kidney prescription diets, giving fluids under the skin, providing medications, and regularly checking lab work.

At home, you can support your cat by keeping them hydrated, helping them maintain a healthy weight, providing a quiet and stress-free environment, ensuring easy access to their litter box, and giving them lots of love and attention. recommends focusing on their quality of life by meeting their basic needs and accommodating any changes (

It’s important to monitor your cat closely for any signs that their condition is worsening, like decreased appetite, weight loss, vomiting, diarrhea or constipation, increased thirst or urination, lethargy, or behavior changes. Alert your vet to any concerning symptoms or changes so adjustments can be made to their care plan.


Treating kidney failure in cats can become quite costly over time. Some of the major expenses include:

  • Diagnostic testing – Tests like bloodwork, urinalysis, ultrasound, and kidney biopsies are often needed to diagnose kidney problems. These can cost $200-500 initially.
  • Hospitalization – Cats with acute kidney injury may need to be hospitalized for IV fluids and medication, at a cost of $1,000-2,000.
  • Medications – Drugs to control vomiting, encourage eating, and manage kidney values typically cost $30-60 per month long-term.
  • Prescription kidney diets – These specially formulated foods average $50-100 per month.
  • Subcutaneous fluids – Administering fluids under the skin at home ranges from $100-300 monthly.
  • Follow-up vet care – Ongoing lab tests and exams to monitor kidney function may run $100-300 every 3-6 months.

In total, managing chronic kidney disease long-term often totals $100-500 per month depending on the treatment plan. Pet insurance can offset some of these costs. Owner vigilance is key to detecting kidney issues early before they become advanced and more expensive to treat.

When to Euthanize

Deciding when to euthanize a cat with kidney disease can be very difficult. As a pet owner, you want to avoid prolonging suffering but also don’t want to make the decision too soon if your cat still has quality of life.

In general, euthanasia may be an option to consider when your cat has severe, unrelenting symptoms, a lack of quality of life, and a poor prognosis. Key factors to consider are:

  • Severity of symptoms – Severe vomiting, lack of appetite, dehydration that cannot be managed at home, severe lethargy, and other symptoms that cannot be controlled may indicate end stage kidney disease.
  • Lack of quality of life – If your cat has stopped eating, is in constant pain, cannot move around freely, no longer seems to enjoy anything, or cannot properly groom, their quality of life may be too poor to continue treatment.
  • Recommendations of vet – Your veterinarian can provide guidance on prognosis and when euthanasia may be most appropriate based on your individual cat’s condition.

According to PetMD, if your cat is in the early stages of kidney disease and you are committed to treatment, they may live for years with CKD. But when they reach end-stage kidney failure, euthanasia may be the most humane option to prevent further suffering. Have an open and honest dialogue with your vet to determine the right time.


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