Eleven Things to Know About Cats with Kidney Failure

Cat Center
cat lying on pillow

If you’re lucky enough to have loved enough cats, you’ve probably been initiated into the club of humans whose cats have lived with, and eventually succumbed to, kidney failure. Kidney failure is that common. And that deadly. But as most of this club’s members will attest, getting a diagnosis of chronic kidney disease doesn’t have to be a tragedy.

After all, cats with kidney disease often live for years beyond their initial diagnosis. To be sure, most do not. And it’s worth noting that some cats are diagnosed only in the disease’s final stages; when there’s not much that can be done beyond offering simple comforts to an end-stage patient’s last days –– or euthanasia, of course.

Still, it’s not all doom and gloom. And I speak from much experience, both as a veterinarian and as someone who’s invested lots of time, energy, and emotion into managing her own cats’ last months with kidney disease.

But even if your cats have never suffered through kidney failure (also commonly referred to as renal failure or chronic renal disease), it’s worth thinking about. Because (let’s be honest), if you love cats like some of us do, you’ll almost surely have to face this issue at some point.

To that end, I’d like to offer what I hope is a super-helpful list of things to consider when you’re dealing with this disease:

#1 Urination and Drinking

These are usually the first symptom owners of chronic renal disease cats notice: Large volumes of urine clotting the clumping kitty litter. And lots of water downed in record time. Though these are sad signs of kidney disease, they’re also an important indicator of the kidneys’ continuing ability to function.

#2 Nausea and Vomiting

When kidneys decline, they can no longer efficiently excrete lots of toxins. That can lead to a major rise in some very nauseating chemicals in the blood. Fortunately, this nausea can be assuaged by a growing arsenal of veterinary drugs designed for this purpose. So, if your kidney-issue cat isn’t eating, ask your veterinarian about these new-fangled nausea-damping drugs.

#3 Fluids

The mainstay of most chronic renal failure patients’ care (especially in their advanced stages) is fluid therapy. Subcutaneous fluid administration is the most common route of fluid input in the long term, though intravenous fluid administration is typically preferred at the outset and may be necessary intermittently throughout the course of the disease.

#4 Anemia

The kidneys make a hormone (erythropoietin) that triggers red blood cell production. This means that when the kidneys suffer, the blood suffers too. Moreover, the excess of fluids these patients sometimes receive means their blood is always more dilute than it would otherwise be, effectively lowering the number of red blood cells making the rounds.

Anemia (low red blood cells in the circulation) is common to chronic renal failure cases and can be managed with nutritional supplementation of iron (to a small degree) and with synthetic or natural hormone supplementation (darbopoetin or erythropoitin, respectively) to a larger degree. But these drugs have side effects, so cats must be managed carefully when they receive them.

#5 Phosphorus

Phosphorus is not your friend during kidney failure. Levels of phosphorus in the blood will rise as the kidneys’ ability to excrete it declines. Consequently, calcium levels rise to match the phosphorus load—and the calcium has to come from somewhere, right? The calcium-rich bones are subsequently leached of their stores, weakening them severely in some cases. That’s why oral, phosphorus-binding drugs are needed to help rid the body of its excessive levels. Ask your vet about these if your cat’s “P” levels are high.

#6 Weakness

Let’s be honest. Cats with renal disease tend to be geriatric. So they’re not only creaky because of arthritis and maybe even a bit touched with dementia, they’re also suffering from all the renal disease issues of anemia, malnutrition, nausea, and weak bones. Which, of course, makes them weak.

#7 Loss of Appetite

A subset of the nausea and vomiting issue (see #2), poor appetite (referred to clinically as “anorexia”) is often the most frustrating aspect of chronic renal failure in cats. That’s why owners will do anything to bring back their kitty’s dinnertime exuberance. Drugs to stimulate appetite can be had. Some are actually moderately effective even when nausea-damping drugs have made no headway. Ask if your kitty’s a candidate.

#8 Weight Loss

Yeah, if you’d been feeling nauseous for weeks or months before your diagnosis, you probably would’ve lost a significant percentage of your body mass too. Keeping tabs on weight is crucial for kidney failure kitties.

#9 Blood Pressure

Here’s a stat for you: Sixty-one percent of cats with chronic renal disease have high blood pressure. But most cats never have this issue addressed (usually through drugs, like amlodipine).

Truth be told, that’s because the other symptoms seem far more pressing, and because we’ve already taken steps to reduce blood pressure through the dietary changes we recommend (see below). Still, I’d consider blood pressure a minimally addressed consideration in kidney failure cats. For some, drugs can make a very real difference.

#10 Diet

By far the most controversial aspect of chronic renal disease therapy, nutritional treatment is nonetheless the most popular approach to mid- to long-term management of feline kidney patients. Low in sodium and protein, these diets are engineered to reduce blood pressure and limit the buildup of toxins.

Unfortunately, getting a nauseous patient to eat is complicated by these diets’ unappetizing approach to protein reduction. After all, our carnivorous cats are built to relish their protein-rich meats. Luckily, plenty of research has gone into these diets and lots of manufacturers are coming up with increasingly appetizing approaches.

By the way, cooking for chronic renal failure kitties is often a fruitful endeavor. Enlist a veterinary nutritionist for this.

#11 Specialists

Finally, let me mention one oft-overlooked feature of treating chronic kidney disease patients: All owners of chronic renal failure patients are welcome to request the advice of a board-certified internal medicine specialist.

Furthermore, owners who choose to consider dialysis (still available only in very limited geographic regions) and the possibility of a kidney transplant (available to limited numbers of renal failure cases) are urged to seek out advanced services as early after the diagnosis as possible.