Get

In Your Inbox

Catster is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

Kidney Disease in Cats: Our Vet Discusses Causes, Signs & Care

vet holding burma cat

Your cat’s two kidneys perform many vital functions in maintaining your pet’s health. They help eliminate toxins from the bloodstream (because they filtrate blood) and maintain water, electrolyte balance, acid-base balance, and blood pressure at normal values. They also regulate circulation and produce hormones (renin and erythropoietin). When the kidneys stop working properly, it can lead to severe health problems that can put your cat’s life in danger.

Cat owners often become worried and confused when they hear that their cat has been diagnosed with kidney disease. Such a diagnosis is never easy. Early detection of the signs of kidney disease is crucial because they usually occur after 75% or more of the kidney function has already been compromised. The sooner your cat is diagnosed, the more you will be able to slow down the progression of the disease.

Since kidney disease generally occurs in middle-aged and older cats from 7 years of age onwards, it is recommended that cats over 7 years be periodically evaluated, ideally every 6–12 months.

divider 3 paws

What Is Kidney Disease?

Kidney disease is a condition in which the kidneys partially or completely lose their ability to function normally. It is a progressive disease in which the products of catabolism and toxic substances are no longer eliminated by the kidneys but retained in the body.

It most frequently affects middle-aged and elderly cats (particularly geriatric cats over 12 years of age) and is the most common cause of death, alongside cancer and heart disease.1 The disease develops over periods of months or years. Approximately 20%–50% of cats older than 15 years have some stage of kidney damage.2 The frequency between the sexes is equal, though males are diagnosed at younger ages than females.

Kidney disease can be acute or chronic, and there are four stages of the disease. They are referred to as IRIS stages. Usually, it’s a chronic illness of older cats, lasting for months and years, while acute onset in younger animals occurs suddenly, often due to toxin ingestion, urethral obstruction, other organ system disease, low blood pressure, bacterial infection of the kidneys, and others. The fourth stage is also referred to as end-stage kidney failure, from which the vast majority of affected cats will not recover.

cat with kidney failure
Image Credit: Lost_in_translation, Shutterstock

Acute Kidney Disease in Cats

Acute renal injury in cats is a condition with a sudden onset resulting from a decline in renal function, which sets in within a few hours or days. The initial clinical signs may include increased urine production, called polyuria, often followed by oliguria (the cat urinates less than usual) or anuria (the cat stops urinating). The cat can be thirsty in the beginning but will soon stop eating and drinking and become very lethargic. Some cats may develop a fever if the cause is bacterial. 

This condition has multiple causes, such as obstruction due to urinary blockage or infection of the renal parenchyma (kidney tissue) and its functional units.

This type of kidney disease can be reversible if the cause is recognized and treated in time.

Chronic Kidney Disease in Cats

Chronic kidney disease (CKD) is a gradual and usually slowly progressive condition in which the functional unit of the kidney, the nephron, loses its functionality over a longer period of time.

When some of the nephrons are damaged, the others take over their function and compensate, but in time, their function will also reduce. This leads to the inability of the kidneys to fulfill their functions of absorption and excretion, making it impossible to successfully eliminate toxins from the body by filtering the blood and producing urine.

divider 3 paws

What Are the Signs of Kidney Disease in Cats?

The clinical signs of chronic kidney disease in cats are progressive and usually begin with an increase in thirst (polydipsia) and the amount of urine produced (polyuria). In general, the owner notices that their cat drinks more water and urinates more than usual. As the condition progresses and becomes chronic, the following signs appear:

  • Lack of appetite
  • Weight loss
  • Specific breath smell (ammonia breath)
  • Vomiting
  • Diarrhea
  • Pale mucous membranes
  • Anemia
  • Mouth ulcers
  • Increase in blood pressure
  • Dehydration

Consulting a veterinarian is recommended for the best course of action.

If you need to speak with a vet but can't get to one, head over to PangoVet. It's an online service where you can talk to a vet online and get the advice you need for your pet — all at an affordable price!

PangoVet_Mention-in-Content for PangoVet2 save money

The more progressive the disease is, the shorter survival time is, as the treatment options are quite limited. Kidney values will eventually increase so much that the cat will not feel like wanting to eat or drink and may stop producing urine in some cases despite treatment. 

Usually, at this time, a vet recommends euthanasia. If euthanasia is not performed, death occurs due to uremia (uremic intoxication), which is when the toxic substances that should be excreted through the urine remain in circulation in such a quantity and time that the body can no longer survive.

Acute kidney injury, or AKI, as already discussed, is rapid in development, and the signs are more obvious and severe. It can occur in cats of any age. It causes the kidney function to suddenly decline, making the cat feel very unwell, as there was no time for compensatory mechanisms present in CKD to properly activate. Acute kidney injury may lead to CKD if the damage to the kidneys is irreversible.

Signs of acute kidney disease

  • Loss of appetite
  • Lethargy
  • Vomiting, sometimes with blood
  • Diarrhea
  • Bad breath (uremic)
  • Mouth ulcers
  • Changes in heart rate and blood pressure
  • Increased or decreased urine production
  • Absent urine production 
  • Enlarged painful kidneys
  • Fever sometimes

Both CKD and AKI require prompt veterinary attention and treatment, but with the acute illness, there is more urgency, as this disease is very progressive, and early treatment may mean the difference between full recovery and ongoing poor kidney function, impacting quality of life and longevity.

cat treated in vet clinic
Image Credit: Raihana Asral, Shutterstock

What Are the Causes of Kidney Disease?

The causes that can reduce the functionality of the kidneys in cats can be congenital, present since birth, or acquired, which is developed throughout the cat’s life and impacted by several different factors. Even congenital kidney disease may take years to exhibit clinical signs. All of them can lead to both acute and chronic kidney disease, while acute kidney injury may progress to CKD.

Certain breeds may be more prone to kidney disease:
  • Abyssinians, Siamese, Burmese, Tonkinese, Devon Rex, and Oriental Shorthair breeds are prone to amyloidosis.
  • Himalayan and Persian are prone to polycystic kidney disease.
Here are the possible triggers that can lead to kidney damage:
  • Systemic infectious diseases (viral or bacterial)
  • Inflammation
  • Secondary kidney infections (glomerulonephritis)
  • Cancer (e.g., lymphoma)
  • Certain nephrotoxic drugs, including human anti-inflammatory drugs (aspirin, ibuprofen, etc.), antifungals, and chemotherapy drugs
  • Other toxins, like antifreeze, toxic flowers (e.g., lily), pesticides, or cleaning products
  • Urinary blockage at the level of ureters or the urethra
  • Kidney stones
  • Thyroid problems
  • Advanced dental disease
  • Trauma
  • Burns
  • Shock caused by massive blood loss or dehydration (e.g., car accident)
  • Heart failure with low blood pressure
  • Heatstroke
  • Pyelonephritis (bacterial infection of the kidneys)

How Is Kidney Disease Diagnosed in Cats?

The diagnosis of kidney disease is usually established by blood tests—more precisely, by measuring urea, creatinine, and SDMA (symmetric dimethylarginine), products of metabolism that are eliminated through the kidneys. In general, these values start to increase from stage two as an early biomarker of kidney disease. Chronic kidney disease has four stages, and the diagnosis is adapted according to them.

Other parameters that can be measured in kidney disease are as follows:

  • Phosphorus is often elevated
  • Electrolytes (sodium, potassium, and chloride) often fluctuate between high and low levels, although potassium is generally low in cases of CKD
  • High potassium levels in case of a urinary blockage
  • Cats with CKD may sometimes have low calcium levels
  • The number of red cells indicates an underlying chronic illness
  • Symmetric dimethylarginine can be used for the early detection of kidney disease
  • Specific gravity of urine determines how diluted or concentrated it is; the higher the number, the more concentrated the urine
  • The ratio between urine protein and creatinine shows how much protein is lost in the urine
  • A urine culture can detect urinary tract infections
  • Cats with CKD often have high blood pressure
  • Abdominal X-rays or ultrasounds can detect kidney stones, kidney enlargement, or stones in the ureters, bladder, or the urethra
devon rex cat examined by vet
Image By: Ermolaev Alexander, Shutterstock

How Do I Care for a Cat With Kidney Disease?

If your cat has been diagnosed with kidney disease, you must follow the instructions of the veterinarian. Depending on the stage of the disease, they will also give you a prognosis:

  • Cats classified in stage two have an average life expectancy of 3 years (up to 8.5 years).
  • Cats classified in stage three have an average life expectancy between 1.8 and 5.7 years.
  • Cats classified in stage four have an average life expectancy of 1.16 months.

Also, cats with kidney failure who follow an adequate diet may have a significantly longer survival time than those who do not consume a special diet.

The ideal diet should have a balanced intake of:

Alternatively, a homemade diet can be taken into consideration if it is formulated by a veterinarian expert in nutrition.

Don’t forget about water! A higher water intake (wet food and/or plenty of fresh water) may help cats suffering from kidney disease. To reduce stress, you can place more litter boxes and offer multiple water bowls. You can also use diffusers with feline pheromones and give your cat a place by a window where they can watch what is happening outside.

Depending on how your cat is getting on, which stage of kidney disease they are suffering from, and how they are responding to the dietary management, they may need extra medication for the high blood pressure or the presence of protein in the urine. Your veterinarian may also recommend periodical intravenous or subcutaneous fluids to your cat, which will help your cat stay hydrated by removing toxins from the blood. These can be administered every few weeks or months.

divider 3 paws

Frequently Asked Questions (FAQ)

Do Cats With Kidney Disease Experience Pain?

Cats suffering from stage four kidney disease may experience pain, which may be due to oral ulcers, inflammation of the stomach lining, and the accumulation of toxins in the blood. They may experience severe weakness, loss of coordination, and collapse. Cats suffering from acute kidney disease may feel pain in the kidney area because the kidneys are often enlarged or swollen. In other cases, when suffering from infections or urinary stones, they may feel pain when urinating.

Can Cat Kidneys Recover?

In chronic kidney disease, once the kidneys have been damaged, the recovery capacity is minimal. If early and adequate management of the disease is installed, it will evolve slowly, and your cat can have several years of quality life. In the case of acute kidney disease, the kidneys can recover if the condition is treated in time. Acute kidney disease can be a reversible condition.

Do Cats With Kidney Disease Meow Frequently?

Excessive meowing is not a characteristic sign of kidney disease, but it can occur. Cats that feel sick and have pain or nausea or have concurrent hyperthyroidism or feline cognitive decline may meow more than usual and become restless. If your cat suffers from kidney disease and meows excessively, take them to the vet. You can also place diffusers with feline pheromones in your home to eliminate stress.

sad lonely cat lying on bed
Image Credit: medveda, Shutterstock

divider 3 paws

Conclusion

The diagnosis of kidney disease is always serious. It is a progressive condition in which cats lose their kidney function. The average life expectancy of cats diagnosed with this disease is approximately two years, but this can vary a lot depending on the time of diagnosis and stage of illness. Due to the toxins that accumulate in the blood, cats will have a general feeling of sickness and nausea. They may also vomit, will easily become dehydrated, and may even experience pain. If your cat is drinking more water than usual and urinating often, contact your veterinarian.


Featured Image Credit: Elpisterra, Shutterstock

How useful was this post?

Click on a star to rate (you can leave written feedback after clicking submit)

Help us improve Catster for pet parents!

Your feedback really matters.

What did you like about this post? Also how can we improve it?

Join the conversation

Leave a Reply

You’re very welcome to leave a comment or question. Please know that all comments must meet our community guidelines, and your email address will NOT be published. Let’s have a positive and constructive conversation.

Talk With A Vet Online

Peace of mind,
anywhere, anytime

Affordable vet advice

Can a Cat Recover From Kidney Failure? Our Vet Explains the Signs, Recovery & Diagnosis

Kidney, or renal failure, in cats is a very common condition. Most cats will suffer from chronic kidney failure, which means that, over...

cat with kidney failure

Polycystic Kidney Disease in Cats: Our Vet Explains the Signs, Causes & Treatment

Most cat owners are familiar with the term chronic renal disease, as it is a widely common disease process that impacts a large...

Veteterinarian explaining to woman cat medical condition

Why Is My Sick Cat Hovering Over Their Water Bowl? (Vet Answer)

A cat’s water intake depends on a number of factors, including their diet, age, and activity levels. However, what if you’ve noticed your...

bengal cat playing water in the bowl

Addison’s Disease in Cats: Our Vet Explains Causes, Signs & Treatments

Addison’s Disease, also known as hypoadrenocorticism, occurs due to a deficiency in adrenal gland hormones. It is a rare condition in cats. The...

vet getting blood sample from cat

More related

vet checking a cat with stroke

Diabetes in Cats: Causes, Signs & Care (Vet Answer)

Diabetes mellitus, often simply referred to as diabetes, is a medical condition that results in consistently high levels of glucose (sugar) in the...

veterinarian listening to cat's heart

Heart Disease in Cats: Our Vet Explains the Signs, Causes & Treatment

Heart disease in cats does not define a single illness, but rather multiple conditions with different levels of severity. Some heart diseases are...

veterinarian doctor holds cat

9 Most Common Illnesses & Diseases in Cats: Our Vet Answers

Cats are masters at hiding signs of illness, no matter what age they are. So, it is important to have an understanding of...

Scared Tabby cat trying to hide

Tremors in Cats: Our Vet Discusses Signs, Causes & Treatment

While the jitterbug may have been a popular swing dance among humans, it’s important to remember that cats don’t normally jitter, the dance...

Keep reading

Why Does My Cat Like Water & Swimming? Vet-Reviewed Feline Behavior Explanation

Cats have a reputation for disliking water. But, while it is true that some of our feline friends detest getting in baths and would never dream of taking a dip in the river or ocean, some breeds love nothing more...

Scottish straight-eared long-haired cat swimming

Can Cats Eat Pesto? Vet-Approved Risks & Safe Alternatives

Pesto is a household staple used in various foods, such as salad dressing, pizza, and chicken—the possibilities are limitless! If you’re a cat owner, you may have noticed your feline nosing around when you bust out this sauce, but is...

Can Cats Eat Pesto

How Long Do Obese Cats Live? Vet Approved Facts & Health Tips

It’s easy for your cat to become obese. They’re too adorable when they beg for food with those big eyes. However, obesity can drastically affect your cat’s lifespan. While healthy cats have been known to live into their 20s, obese...

white-cat-laying-on-the-animal-scales-while-the-male-vet-measure-weight_Odua-Images_Shutterstock

9 Best Cat Beds for Anxiety in 2025 – Reviews & Top Picks

Cats can be particular about their bedding, but for cats with anxiety, choosing the right bed can ensure your cat has a sense of safety and security. Cozy, anxiety-reducing beds can be a fantastic tool in helping improve your cat’s...

Ragamuffin cat hiding

Can Cats And Dogs Drink From the Same Water Bowl? Vet Approved Facts & Tips

If you live in a multi-pet household and own both a cat and a dog, you may be wondering if these animals can share their water bowl. If your cat and dog choose to drink out of the same water...

Can Cats And Dogs Drink From the Same Water Bowl

Can Cats Eat Catfish? Vet-Approved Nutritional Facts & Advice

No, it’s not cannibalism! Cats love to eat up a fishy treat from time to time. While catfish might be named for our feline friends and have no scales, in our cats’ eyes (or tastes), it makes no difference. Fish...

Can Cats Eat Catfish

How to Tell if a Cat Is Scared (4 Vet-Reviewed Signs to Look For)

One of the hardest parts of being owned by a cat is not always knowing exactly how they’re feeling. As typically stoic animals, it can be difficult to tell if your cat is in discomfort or feeling vulnerable in some...

cat hiding

Alternatives to Declawing Your Cat: 8 Humane Options

On paper, declawing your cat might seem like a simple way to stop your furniture from being ripped to shreds, but the reality is that it’s a cruel and painful operation that can lead to long-term pain, discomfort, and behavioral...

cat claw