Cats with kidney-related concerns may not always show obvious changes at first.

That is one of the most important things I want cat guardians to understand. A cat may seem fine on the outside, but small changes in appetite, drinking habits, urination, vomiting, or energy level can be important signs.

As a veterinarian who specializes in cats, and as the guardian of Minky, a cat who lived to the age of 28, I have learned that caring for cats with kidney-related concerns requires careful observation, regular monitoring, and an understanding of each cat’s normal daily behavior.

Kidney-related health concerns can happen at any age.
But receiving a kidney-related diagnosis does not mean a cat will pass away immediately.

What matters is how closely we observe them, how consistently we monitor their condition, and how quickly we respond when something changes.

One Blood Test Is Not Always Enough

A single increase in creatinine does not automatically mean a cat has a chronic kidney condition.

In many cases, a chronic kidney condition is considered when abnormal kidney values continue over time. For example, when abnormal kidney-related values persist over time, veterinarians may consider the possibility of a chronic condition in the context of the cat’s overall clinical picture. 

Test results can also be affected by the cat’s condition before the exam. In some cases, recent food intake or the cat’s condition before testing may influence certain laboratory values.

That is why following the veterinarian’s testing instructions, including fasting recommendations when appropriate, can be important. 

For cats already diagnosed with kidney-related concerns, regular testing is important.

In general, stage 1 cats may be checked every 6 months to 1 year. Stage 2 cats may be checked every 3 to 6 months. Stage 3 cats may need testing every 1 to 3 months. For stage 4 cats, the testing schedule should depend on the cat’s individual condition and the need to manage complications.

Know Your Cat’s Normal Behavior

Cats with kidney-related concerns often do not show many clear symptoms.

Because of this, guardians need to know what is normal for their own cat. The small differences matter.

Vomiting, loss of appetite, refusing food even when the cat seems interested in eating, crouching in a corner, or showing less energy than usual can all be signs that something is wrong.

A sudden increase in drinking or urination should also be taken seriously. Many people say that drinking water is good for cats with kidney-related concerns, but if a cat suddenly drinks much more water or urinates much more than usual, it may be a sign that the cat should be checked by a veterinarian.

Litter box behavior is also important. In cases of acute kidney failure, many guardians first notice something is wrong because the cat cannot urinate. If a cat keeps going in and out of the litter box, but there are no urine clumps, this should be taken very seriously. In that situation, the cat must be taken to the hospital.

Picky Eating Can Be a Warning Sign

Cats are hunters by nature.

For an indoor cat, dry food, wet food, and treats can all be seen as forms of prey. So if a cat suddenly becomes picky, chooses only certain foods, or refuses regular meals, guardians should not simply dismiss it as a preference.

In my opinion, when a cat’s appetite decreases or the cat starts gagging, it can be the beginning of illness.

Many guardians may think, “Maybe my cat is trying to throw up a hairball,” “Maybe they ate too fast,” or “Maybe they ate too much.” But these signs should be watched carefully.

If a cat continues to be picky or stops eating proper meals, it is better to visit the hospital.

What to Do When a Cat With Kidney-Related Concerns Vomits

When a cat vomits, many guardians want to feed them right away because they worry the cat is hungry.

But vomiting can happen because there is a problem with the stomach. It may be related to stomach acid, excess acid, or even a gastric ulcer. If the stomach is not ready to accept food, feeding too soon can make the cat vomit again and feel worse.

If a cat vomits, I usually recommend withholding food and water for about four to five hours and observing them.

After that, if you try to offer a small amount of food and the cat turns their head away, that can mean there is a problem. In that case, it is better to go to the hospital.

If a cat vomits three or more times in a row, or continues vomiting for more than three days, the cat should be seen by a veterinarian. If the cat’s appetite drops, seems nauseous, or continues vomiting even after care at home, it is best to visit the hospital as soon as possible.

For cats who vomit frequently, guardians should ask their veterinarian in advance what steps to take at home and when to visit the clinic.

Kidney Health Care Is About Watching the Small Changes

Kidney-related care is not only about bloodwork numbers.

It is also about the small signals cats show in daily life. A change in appetite, a different posture, less energy, more drinking, more urination, repeated vomiting, or unusual litter box behavior can all be meaningful.

Cats cannot explain their discomfort in words.
So guardians must learn to read their cat’s language through behavior.

A kidney-related diagnosis is not the end. But it does mean the cat needs more careful observation, regular testing, and timely veterinary care when something changes.

For cats with kidney-related concerns, long-term care begins with knowing what is normal for your cat and noticing when that normal begins to change.

Watch the full interview with Dr. Kim Jae-young here: 

About the Author Dr. Kim Jae-young, DVM First President of the Korean Society of Feline Medicine President of Veterinarians without Borders Korea Cat Specialized Clinical Veterinarian with 35 Years of Experience Feline Anti-aging and CKD Specialist