Published by: Ingrid King. Last Updated on: June 28, 2023 by Crystal Uys

vet holding a senior cat

Written by Renee L. Austin

As cats age, we watch for physiologic changes that may affect the long term outlook for health. Many health concerns arise because we notice shifts in behavior, appearance, and activity levels. One condition associated with aging and cats is so inconspicuous that once the physical signs do become apparent, the disease is already quite advanced.

Chronic Renal Disease or Chronic Renal Failure (CRF) is often seen in aging cats. It results in a gradual decrease in the function of the kidneys. The kidneys serve a number of purposes; they produce urine and filter waste products from the body, regulate electrolytes such as potassium and phosphorous, they produce erythropoietin which stimulates red blood cell production by the bone marrow, and they contribute toward regulating blood pressure. Once the loss of function begins it is not reversible, and other vital organs are affected along with how your cat may feel in general.

Signs of CRF can be very subtle at first, especially with a species that relies upon masking illness and appearing healthy for its survival. Watch for increased thirst and urination, vomiting or other signs of nausea, lethargy or depression, poor hair coat, loss of appetite, lingering over the water bowl, eating cat litter, constipation, a strong ammonia-like odor to the breath, and changes in vision and hearing.

CRF is diagnosed beginning with a thorough physical examination and simple diagnostics run through your veterinarian’s office. Changes in the kidneys’ ability to concentrate urine and flush out waste are one of the earliest means of detecting the disease and will be assessed in a urinalysis. Blood tests will check for increases in Blood Urea Nitrogen and Creatinine to determine whether there is waste ‘build-up’ in the blood. Any changes in electrolyte levels and general blood cell health will be measured as well. Your cat’s doctor will also want to monitor blood pressure and perform a careful eye exam which may include measuring ocular pressures.

Veterinarian examines white cat
Image Credit: Hananeko, Shutterstock

There is no cure for CRF, but once it is diagnosed there are a number of actions you can take to help slow its progression and keep your cat comfortable at home. Dietary management, supplements, medication, and fluid therapy are all options that your veterinarian may discuss with you.

It is best to catch CRF before you notice signs at home by making routine visits to your veterinarian for examinations and lab work.  By doing this, subtle changes can be detected and monitored over time and preventative measures can be taken in the earliest stages. A good dental maintenance program will also help support overall organ health. Once-a-year visits may be appropriate for the younger feline, but as the years advance, more frequent visits might be in order.

Changes that occur as cats age are complex, and signs of CRF can be similar to many different disease processes. Be certain to make those appointments with your veterinarian and work closely together to understand your cat’s aging issues, as well as steps you can take to manage Chronic Renal Failure.

Renee Austin Renee L. Austin is the founder of Whimsy Cats, a specialized home care business for cats with chronic medical conditions and special needs. She also provides consulting services for veterinary practices. For more information visit


Featured Image Credit: Alice Rodnova, Shutterstock

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11 Comments on Chronic Renal Disease in Cats: Signs, Diagnosis & Care

  1. Just a quick update, we’ve had a couple of friends over who hadn’t seen Jackie in a couple weeks or more and they say she looks like she has really turned a corner and is gaining weight and looking a lot better although she’s still thin.

    Tom Mary Beth and the Furries.

  2. Yeah it sure is Ingrid, like I say I know she’s not out of the woods yet but this is a great improvement. The food she is eating the best right now is the Stella and Chewy’s dehydrated stuff, we rehydate it either in water or we put it in some of the gravy from the Weruva and she really likes it. She still goes and eats some of the Weruva or nature’s variety canned but she just kind of licks at it vigorously and eats it slowy. Her appetite has greatly improved, we’re giving her small meals wheneber she wants at this point to help her put some weight back on.

    Best regards,

    Tom Mary Beth and the Furries.

  3. Hi Ingrid and all.

    Well we got a great Christmas present late. I had called Jackie’s vet to see if they carried renovast to get her put on that as soon as possible. One of her docs called back the day after Christmas and Mary Beth proceeded to ask her about this. Our vet was surprised, she said someone should have told us, they did another blood panel the day they let Jackie come home from the hospital after being treated for pancreatitis which she also had and the kidney problem by being hydrated for two days. Anyhow, her kidney values have completely resolved and are back in the normal range. Her vet did say we will need to continue to monitor her closely she is still not well, still very thin. The good news is her appetite continues to be great since she’s been home.So while she’s not out of the woods yet things are greatly improved for now. Definitely the best Christmas present I got.

  4. Thanks Ingrid, yes this is going to be very difficult. Fortunately a neighbor of ours who is a good friend and also a cat person knows how to do sub-cu fluid when Jackie gets to that stage. She is continuing to eat pretty well I am glad to say, we got a couple of kitty fountains set up in here to hopefully attract her and the othrs to water, they always had access to water but just in one of those water dispensing containers, not very interesting. I am going to ask our vet about the renovast supplement, waiting to hear back from them now. So that’s where we are at the moment.

    Tom Mary Beth and the furries.

  5. A good post as usual. Unfortunately we hav recently learned that our Jackie kitty is developing this. She had to be hospitalized this week because she was not eating well and was getting dehydrated. She is back home today and is doing much better, we’ll see how the eating goes in a while here.

    Best regards,

    Tom Mary Beth and the Furries.

  6. Mason, Yes-it’s definitely a good idea to keep an eye on Little One. There are other medical reasons that might contribute to increased thirst (such as diabetes). Of course, exercise, boredom, and just plain fun like playing in the water dish or fountain can be reason enough to drink, too! Thanks for your comment!

    Thank you, Ingrid!


  7. Thanks for the wonderful post. Definitely things one needs to keep a check on. I know you’ve peaked my interest because I’ve noticed Little One drinking more lately, but seen none of the other signs mentioned. Usually her drinking was after she’d been running and playing a good bit. But something I will watch much closer now. Thanks.

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