Kidney Crisis. Can Kidney Disease Strike Cats Suddenly?


Kidney disease is common in cats, especially as they age. The kidneys are responsible for filtering waste from the blood, regulating body fluid levels, and producing urine. Kidney disease refers to any condition that impairs kidney function. It can range from mild dysfunction to complete kidney failure (Marino 2014).

While chronic kidney disease that progresses slowly over months or years is most common, some cats can develop sudden (acute) kidney injury that deteriorates quickly over days or weeks. This acute kidney disease can be very dangerous if not treated promptly.

Signs of Kidney Disease

There are several common signs of kidney disease in cats to look out for. These include:

Increased thirst – One of the earliest signs of kidney problems is increased thirst. Cats may drink noticeably more water when their kidneys are not functioning properly. This is due to the kidneys being less able to concentrate urine, leading to excess urination and dehydration.

Increased urination – Along with increased thirst, cats with kidney disease often urinate larger volumes and more frequently. Urine may also appear more diluted. This is again related to the kidneys’ reduced ability to concentrate urine (Source).

Weight loss – Appetite changes and weight loss are common signs of kidney disease. When kidneys are impaired, toxins build up in the blood which can cause nausea and poor appetite. Cats gradually lose weight as they eat less food.

Poor appetite – Decreased appetite is frequently seen with kidney problems. Toxins in the bloodstream lead to nausea and oral ulcers which make eating painful. Even favorite foods may be refused or only eaten in small amounts.

Vomiting – Some cats with kidney disease vomit periodically. This is often related to nausea from the buildup of toxins in the body (Source).

Acute vs Chronic Kidney Disease

Kidney disease in cats can be broadly categorized as either acute or chronic. Acute kidney disease comes on suddenly, while chronic kidney disease is a gradual process that worsens over months or years. Both acute and chronic kidney disease can become serious if left untreated.

Acute kidney disease, also called acute kidney injury (AKI), involves a rapid decline in kidney function over days or weeks. It’s usually caused by a sudden event like ingesting toxins, an infection, or low blood flow to the kidneys. Cats with AKI may show signs like vomiting, diarrhea, lack of appetite, and increased thirst and urination. AKI requires quick veterinary treatment to try to halt further kidney damage.

Chronic kidney disease (CKD) involves the gradual loss of kidney function over time. It’s most often seen in older cats. Early signs are mild and develop slowly, like weight loss and increased thirst. Without treatment, CKD leads to buildup of toxins and fluid imbalances that make cats very ill. CKD is managed with medications, diet changes, and hydration therapy. While incurable, treatment can slow progression and extend lifespan.

The main difference is AKI happens abruptly, while CKD develops incrementally. However, both indicate serious underlying kidney damage. Sudden onset of any signs of kidney failure warrants an urgent vet visit to determine the cause and start proper care.

What Causes Sudden Kidney Disease?

There are several potential causes of sudden (acute) kidney disease in cats:

Toxins like antifreeze (ethylene glycol) can cause severe damage to a cat’s kidneys leading to acute kidney injury. Even small amounts of antifreeze can be extremely toxic. According to the Pet Poison Helpline, as little as a teaspoon can be fatal for a cat. The toxic agent in antifreeze is ethylene glycol. When ingested, it’s metabolized into highly toxic compounds that damage the kidneys.1

Urinary tract obstructions that prevent a cat from being able to urinate can quickly cause kidney damage. This is often caused by kidney stones or crystals, urethral plugs, blood clots, or even tumors blocking the urinary tract. The inability to pass urine causes rapid buildup of toxins and fluid imbalance that harms the kidneys.

Cancer, like lymphosarcoma, can also spread to the kidneys and cause kidney failure. Tumors growing in the kidneys can impair kidney function.

Infections such as pyelonephritis, an inflammation of the kidney tissue due to bacterial infections, can occur suddenly and lead to acute kidney problems. Upper urinary tract infections that spread to the kidneys are a common cause.

There are some other rarer causes like glomerulonephritis, an inflammatory disease of the glomeruli in the kidneys, that can also cause acute kidney disease in cats.

Diagnosing Sudden Kidney Disease

If a cat is showing signs of sudden kidney disease, the vet will perform a full physical exam and ask about the cat’s medical history. They will feel the abdomen to check for enlarged kidneys, take the cat’s temperature, and assess hydration status by checking the gums and skin for tackiness.

The most useful diagnostic tests for kidney disease are blood and urine tests. These allow the vet to assess kidney function by looking at waste products in the blood like creatinine and BUN. Elevated levels indicate the kidneys are not properly filtering toxins from the blood. Urinalysis checks urine concentration and looks for protein loss into the urine, both signs of kidney disease [1].

The vet may also recommend x-rays or ultrasound to check kidney size and shape and look for underlying issues like kidney stones. In some cases, biopsy of the kidney may be needed for a definitive diagnosis. But in an emergency situation, blood and urine tests are the quickest methods for diagnosing sudden kidney problems in cats.

Treating Sudden Kidney Disease

The main treatments for sudden (acute) kidney disease in cats revolve around supportive care to stabilize the cat while the kidneys recover. This usually involves intravenous (IV) fluid therapy, medications, and dietary changes.

IV fluid therapy is crucial for flushing toxins from the bloodstream and restoring hydration and electrolyte balances. The fluids used contain electrolytes like potassium that are lost during kidney injury. The rate of fluids depends on the cat’s needs and is adjusted based on labwork results (Embrace Pet Insurance).

Medications may include:

  • Diuretics to increase urine output
  • Anti-nausea medication
  • Kidney supplements
  • Phosphate binders if high phosphorus is an issue

Dietary changes involve feeding a low protein, low phosphorus prescription kidney diet, which reduces strain on the kidneys. Cats with anorexia may need to be force fed or fed via a feeding tube.

The specific treatments given will depend on the underlying cause and the cat’s condition. Severely ill cats may need dialysis to filter the blood. With aggressive therapy, many cats can recover normal or nearly normal kidney function.

Supportive Care at Home

There are several things you can do at home to provide supportive care for a cat with kidney disease:

Encouraging Eating: Cats with kidney disease often have a reduced appetite. Make sure fresh water is always available. Hand feed small frequent meals of their favorite foods. Warm the food to enhance smell and taste. Mix the food with tuna juice, low-sodium broth or gravy to increase palatability. Assist feeding with a syringe if needed. (1)

Subcutaneous Fluids: Dehydration makes kidney problems worse. Giving subcutaneous fluids under the skin helps flush toxins and provides hydration. Your vet can show you how to administer fluids at home. Fluid frequency depends on your cat’s needs. (2)

Monitoring Litterbox: Measure your cat’s urine output and notify your vet of any significant changes. Straining, bloody urine, or lack of production can indicate a kidney blockage requiring prompt veterinary attention.

With dedicated home care and treatment, many cats can live comfortably with kidney disease for months or years. Monitoring your cat’s eating habits, activity levels, and litter box usage is key. Always consult your veterinarian if you have any concerns.

Preventing Sudden Kidney Disease

While kidney disease often cannot be prevented entirely, there are steps cat owners can take to reduce the risks and promote kidney health:

Avoid toxins. Keep medications, chemicals, antifreeze, plants toxic to cats, and other dangerous substances safely out of reach. Reduce exposure to heavy metals and other environmental toxins as much as possible.

Ensure proper hydration. Make fresh, clean water easily available at all times. Consider adding extra water sources around the home. Feed wet food, which has high moisture content. Talk to your vet about supplements or fluids if needed.

Feed a kidney-friendly diet. Choose a high quality cat food designed for kidney health, with reduced protein, phosphorus and sodium. Homemade and raw food diets must be formulated properly.

Have regular vet checkups. Annual exams and bloodwork allow early detection of reduced kidney function before symptoms appear. This allows earlier intervention.

While kidney disease cannot always be prevented, these measures help support kidney health and reduce risk in cats.


The prognosis for cats with acute kidney disease depends on the underlying cause and how quickly treatment is started. With aggressive therapy, many cats can recover normal or near-normal kidney function. However, acute kidney injury can be fatal if not treated promptly.

According to PetMD, the prognosis is generally good if treated within 48 hours of the onset of symptoms. Unfortunately, about half of cats with untreated acute kidney failure will not survive. Of those that do recover, 25-50% are left with some permanent kidney damage.

The key is to get veterinary care as soon as any signs of illness are noticed. With early intervention, supporting kidney function, and treating the underlying cause, the prognosis can be quite good. Acute kidney disease may be reversible if caught and managed quickly before substantial, permanent damage occurs.

When to See a Vet

If your cat is exhibiting any symptoms of kidney disease, even subtle ones, it is crucial to seek veterinary care immediately. The earlier kidney issues are caught and treated, the better the prognosis. Some signs that warrant an urgent vet visit include:

  • Increased thirst or changes in water consumption
  • Changes in urination frequency or amount
  • Weight loss
  • Reduced appetite or refusing food
  • Vomiting
  • Diarrhea
  • Lethargy
  • Poor coat condition

Catching kidney disease early allows vets to diagnose the underlying cause and start treatment right away. This gives your cat the best chance possible for managing symptoms and slowing the progression of kidney damage. Even if you only notice subtle changes in behavior, it’s better to have your vet examine your cat sooner rather than later. Don’t wait until symptoms become severe. With prompt veterinary care and following your vet’s treatment plan, you can gain more quality time with your beloved feline companion.


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