Feline Chronic Kidney Disease: What Every Cat Owner Should Know

Text and photos by JaneA Kelley

Kidney disease is one of the most common illnesses that afflict elder cats. Almost every older cat will end up having some degree of chronic kidney disease. In fact, my 17-year-old cat, Thomas, is one of those “kidney kitties.”

Before I get into explaining kidney disease, I’m going to start with a primer on what the kidneys do and how they do it. The kidneys, which are two small organs that live just below the rib cage on either side of the spine, remove waste and extra water from the blood. That water, laden with the body’s wastes, becomes urine, which flows from the kidneys to the bladder through ducts called ureters. From the bladder, the urine gets to the outside of the body and into your cat’s litter box through the urethra.

Chronic kidney disease happens when the structures in the kidneys that remove waste and water from the blood begin to shrink and then stop working as well. This is one of the reasons why the clearest sign of kidney disease is that your cat will drink and pee much more than usual. Ailing kidneys make much more urine in an attempt to get wastes out of the body, and because of all that urination, a cat with kidney disease gets thirstier and drinks more water. Thomas certainly lived (and continues to live) up to this symptom: I have a pot of water on my stove just for him, and he drinks out of it many times each day.

But even with all that drinking and peeing, waste and acid builds up in the body and makes a cat feel “kinda punky,” as my vet puts it. A cat with chronic kidney disease may be lethargic and reluctant to eat due to nausea caused by the wastes in the body. You may also notice that in a cat with kidney disease, the fur coat becomes oily and just not very well maintained. Thomas’s coat is still pretty good, but then again, he’s quite “well polished” due to lots of petting, and he eats a very healthy diet.

Another thing that can happen in cats with kidney disease is constipation. Because the kidneys are constantly pulling water out of the blood, this leads to less water in the intestines, which can cause stools to become hard and difficult or painful to eliminate. Thomas has definitely suffered from constipation.

Anemia is a particularly dangerous complication of chronic kidney disease. The illness affects the body’s ability to produce oxygen-carrying red blood cells, and a cat with anemia generally has very pale or even white gums. I recently took Thomas to the emergency vet because I noticed that his gums seemed really pale, and he’d been lethargic. The good news is that he didn’t have anemia, but he was pretty dehydrated. They gave him some subcutaneous (a.k.a. subQ) fluids and he felt much better.

Kidney disease in cats has stages that indicate the progression of the disease. The guidelines used by veterinarians are produced by the International Renal Interest Society, more commonly known as IRIS. They revolve around the presence of a waste product called creatinine in the blood, protein in the urine, and blood pressure. A measurement called blood urea nitrogen also increases with kidney disease, although that could be attributed to dehydration rather than kidney disease. When the emergency clinic ran Thomas’s blood work, his creatinine was at 3.9, which places him in Stage 3.

So, how do I live with my “kidney kitty” and make him feel as good as possible? First of all, Thomas also has hyperthyroidism, so he gets his dose of Felimazole every day. He and my other cats get a species-appropriate diet—in my cats’ case, that means raw food. (My vet knows I feed raw, and she has been very supportive of that.) Under my vet’s direction, I add a small amount of unflavored Miralax powder to his food so that he can stay “regular” and not cry in pain when he poops. I make sure he has his pot of water on the stove so he can drink whenever he needs to. And of course, I give him lots of love.

I’ve also recently started him on subQ fluids. He gets 100ml of Lactated Ringer’s twice a week. And he’s been so good for me, not running away when I poke the needle in, sitting still while the fluids go in, and so on. One of the veterinary nurses at my clinic gave me a demo on how to give the fluids, and since I’ve given cats just about every kind of medication you can think of, it wasn’t a challenge for me.

There’s a whole array of medications and supplements you can give a cat with kidney disease. There are medicines that control phosphorous and calcium imbalances that are common in feline CKD. Probiotics, anti-nausea medications, and some herbal remedies can help control symptoms like constipation and that whole “feelin’ kinda punky” thing. These medications should be discussed with your vet.

Some vets will recommend that cats diagnosed with chronic kidney disease eat a special prescription low-protein diet, which is designed in theory to put less pressure on the kidneys. You can talk to your vet about this, but I can tell you that even though my Thomas is in stage 3 kidney disease, my vet has never recommended that I feed him that low-protein prescription diet. Whatever decision you make about your kidney kitty’s diet, I strongly suggest that you do it under your vet’s guidance.

If you have a cat who’s just been diagnosed with chronic kidney disease, you may be feeling overwhelmed. That’s a common thing when a person finds out their beloved cat has a chronic illness. The good news is that there are some amazing resources available on the internet, the best and longest-running of which is Tanya’s Comprehensive Guide to Chronic Kidney Disease. It provides a lot of information about the staging of kidney disease and treatment options. You can also find tips and tricks to make administration of subQ fluids easier and get support from other people whose cats have CKD.

As for life expectancy, the prognosis varies with each cat. Thomas has been in stage 3 for years now, but some cats get very sick, very quickly. There’s no way of knowing which cat your cat will be. My advice to you: Enjoy every single moment you have together and don’t spend a lot of time worrying about the future.

Chronic kidney disease is, unfortunately, not a condition that can be cured. The damage to the kidneys can’t be undone. But by treating the symptoms of the condition such as dehydration, nausea, constipation, or anemia, you can give your “kidney kitty” a great quality of life until it’s time for them to shuffle off their mortal coil.

JaneA Kelley is the webmaster and chief cat slave of Paws and Effect, an award-winning advice blog by cats, for people and their cats. She writes a regular column for Catster Magazine and is an occasional contributor to the Catster website. When she’s not blogging, she works as a content writer for a digital marketing company to pay the bills, and she gets outdoors whenever she can. She lives in Seattle with her cats, Thomas, Belladonna, and Tara.