What is chronic kidney disease in cats?
CKD happens when the kidneys slowly lose their ability to filter waste and balance fluids. These changes usually happen over the course of months or years. In the early stages, you may not notice anything different at all. As kidney disease progresses, waste can build up in the blood, and your cat may begin to feel tired, nauseous, or less like themselves.
Even though CKD is a long-term condition many cats with kidney disease continue to enjoy a good quality of life with supportive veterinary care, regular monitoring, and simple adjustments at home.
Understanding what’s happening inside your cat’s body is the first step toward making confident choices. The key is working closely with your vet so you can stay ahead of changes as they happen.
What are common signs of kidney disease in cats?
Cats are very good at hiding when they don’t feel well, so early signs of kidney disease in cats can be easy to miss. In the earliest stages, cats with CKD may not show any symptoms at all.
Below, we've shared a list of the most common symptoms of kidney disease. Though they don’t confirm CKD on their own, your cat should be seen by a vet if they show one or more of them.
● Drinking more water
● Peeing more often or making larger litter clumps
● Eating less or being more selective about food
● Losing weight or appearing thinner
● Vomiting or acting nauseous
● Bad breath, especially with an ammonia or chemical smell
● Sleeping more, hiding, or acting withdrawn
● A dull or messy coat
These signs can also appear with other illnesses, which is why diagnostic testing is often recommended to determine whether the cause is kidney disease or something else.
You know your cat better than anyone, so let your vet know if you notice any changes.
What causes CKD in cats?
There’s usually not one single cause of CKD. It is more common in older cats (specifically, cats over the age of 10), which is one reason regular checkups become even more important as cats enter their senior years.
Some cats may have had a kidney infection earlier in life, long-term inflammation from unrelated diseases, high blood pressure, or exposure to toxins. However, kidney disease can also happen without a clear trigger.
Even when the specific cause isn’t known, your vet can test how your cat’s kidneys are working today and make a plan that supports their long-term comfort.
How do vets diagnose CKD?
Regular preventive care can help detect early changes in kidney function—sometimes before you notice symptoms.
If you do see something concerning, your vet will gather information from you and perform a thorough physical exam. Since CKD signs can look like many other health issues, and sometimes shows no signs at all, they may use a combination of tests to understand what’s happening inside your cat’s body:
Blood tests
Your vet might start with blood testing, which provides an overall picture of your cat's internal health. Blood work includes kidney values, which offer clues on how well the kidneys are filtering blood. Blood testing can also tell whether your cat is making enough red blood cells, which can decrease in cats with CKD, causing anemia. Anemia means the blood is not able to carry enough oxygen throughout the body, which can lead to weakness and shortness of breath.
Urine test
Urine (pee) evaluation is another basic test that provides information about your cat's health status. It shows how well the kidneys are concentrating pee, which is a process that removes most of the water from the urine so the cat does not get dehydrated. It also helps determine whether protein or infection are present. Kidneys that are working normally don't allow protein to enter the urine, so if protein is found, especially if the urine is not well-concentrated, it can mean the cat has kidney disease.
Blood pressure
The kidneys are part of a complex system that regulates blood pressure. When kidney function falls, blood pressure can become elevated. Blood pressure checks are important because high blood pressure can eventually cause damage to the eyes, heart, and brain.
Imaging
In some cases, X-rays or an ultrasound can give more information about the kidneys’ size and shape. Cats with CKD may have kidneys that are small or lumpy.
No single test tells the whole story. Taken together, these results allow your vet to tell how severe your cat's kidney disease is and set a clear plan for ongoing care. With this information, you can make informed, proactive choices and avoid guesswork.
Staging CKD
After diagnosis, your vet will stage your cat's kidney disease. There are four cat kidney disease stages, ranging from mild to severe. Here's how they break down:
● Stage 1 kidney disease in cats: Mild disease with minimal lab changes; some cats may not show signs at this point.
● Stage 2 kidney disease in cats: Mild disease with moderate lab changes; some cats may start to show subtle signs.
● Stage 3 kidney disease in cats: Moderate disease with more advanced lab changes; some cats may have more apparent symptoms at this stage.
● Stage 4 kidney disease in cats: Severe disease with significant lab changes; some cats show obvious signs with advanced disease. This represents end-stage kidney disease in cats.
How do vets treat CKD in cats?
CKD can't be cured, but it can be managed in ways that help your cat feel better and slow the disease’s progression:
● A kidney-friendly diet is often a major part of care. Cat kidney disease diets include specific amounts of minerals and nutrients to reduce the workload on the kidneys and slow disease progression. When kidney disease is found early, a kidney-friendly diet may help your cat live a longer, healthier life.
● Making sure your cat drinks enough water is also essential. Some cats drink more when given multiple water sources or a fountain. Others feel better with fluids given under the skin at home, which is something your veterinary team can teach you if it’s right for your cat.
● Your vet may also prescribe medications to ease nausea, improve appetite, manage blood pressure, increase red blood cell production, and help balance minerals in the body. Only give your cat medications if prescribed by your vet.
Over time, your vet may adjust your cat’s plan based on follow-up tests. Regular monitoring can help catch small changes early and keeps your cat feeling their best.
How can you care for a cat with CKD at home?
Taking care of a cat with chronic kidney disease can feel like a lot at first, but the good news is that the small things you do each day really matter. Here are some tips that can help:
● Keep fresh water available in more than one place.
● Make sure your cat is eating. Some cats prefer their food to be slightly warm or served in smaller, more frequent meals.
● Keep litter box areas clean, quiet, and easy to reach.
Sharing with your vet the small details you notice at home—like how much your cat drinks, how well they’re eating, and how energetic they seem—can help shape the best care plan for your cat.
When should you see your vet?
If your cat stops eating for more than a day, vomits repeatedly, or shows a big change in drinking or peeing habits, reach out to your vet.
If your cat has trouble breathing, sudden weakness, seizures, or collapse, contact your vet or the nearest emergency veterinary clinic right away.
Whenever something doesn’t feel right, it’s always safest to call your vet. They can help guide you on what to do next.
How to prevent kidney disease in cats
Unfortunately, many cases of kidney disease can't be prevented. This is why regular vet visits are so important. If your vet detects early kidney disease during a routine wellness check-up, they can start treatment to slow progression of the disease. By the time cats show signs of CKD, the disease is often advanced and treatment may not be as effective.
Staying on top of your cat's health
Although your cat's body systems may slow down as they age, knowing about CKD can help you stay ahead of changes that affect their quality of life. With early detection and treatment, cats can often enjoy many more months or years. With routine screening, some cats are diagnosed with early CKD before they ever become sick. Staying on top of minor changes in your cat's health and seeing your vet regularly can help your cat feel their best for as long as possible.
Frequently asked questions
Frequently asked questions about this topic
Every cat is different. Many cats can do well for long periods of time with careful monitoring, a kidney-focused diet, and supportive treatments. Your veterinarian can offer a clearer outlook based on your cat’s test results and how they respond to care.
Kidney-focused diets are one of the most effective ways to support cats with CKD. Your veterinarian may recommend one based on your cat’s blood and urine tests. If your cat is picky or hesitant, your vet can help you with a slow transition plan or explore different kidney-safe options.
CKD itself usually isn’t painful, but it can cause symptoms, like nausea or dehydration, that may make your cat uncomfortable. Many of these can be managed with medicine, fluids, or diet changes. Tell your vet if you notice signs of discomfort so they can help.
In many cases, CKD cannot be prevented. Unfortunately, the condition is common in older cats and often develops without a clear cause. What matters most is working with your vet now to support your cat’s health and comfort.
A cat's kidneys are made up of filtering units called nephrons. If nephrons are damaged, it is typically irreversible and cumulative damage over time can cause them to deteriorate and worsen over time, leading to a gradual decline in kidney function. When a significant portion of nephrons are lost, kidney disease is typically the result.
