*This article is not a substitute for veterinary advice. Your veterinarian can provide personalized suggestions relevant to your cat’s unique situation.
There’s no way a short article can tell you everything you need to know about kidney disease nutrition. Years of scientific research and experience have left CKD cat guardians, seasoned veterinarians, and scientists with more questions than answers.
In this article, we’ll explore the dynamic and complex relationship between diet and feline kidney disease.
You’ll learn how the best cat food can help your cat feel better longer, identify the key qualities of a good food for CKD kitties, and get to know five of the most popular renal diets on the market in 2019.
Once your cat has lost kidney function, they can’t get it back – but the right food makes the future brighter.
Feeding your cat the right food is the best way to slow the disease’s progression, minimize symptoms, and give your cat the best life possible.
The best foods for kidney disease improve your cat’s quality of life by keeping your cat hydrated, supporting lean body mass, and reducing toxins in the bloodstream.
Our Top 3 Recommended Wet Food For kidney disease
Royal Canin Veterinary Diet Renal Support D Morsels
Hill’s Prescription Diet k/d Kidney Care
Hi-Tor Neo Diet For Cats
Royal Canin Veterinary Diet Renal Support S Dry Cat Food
Prescription Cat Food for Kidney Disease – Good or Bad?
Decades of research tell us that the best food for cats with CKD are those with the following qualities:
- High calorie density
- High quality protein
- Low phosphorus levels
- Increased B vitamins
- Omega-3 fatty acids
Even the best commercially-sold conventional diets don’t do all of these things at once. This leaves you with a couple of options.
You can hold your nose over the questionable protein levels, high carbohydrate content, and unwholesome additives in a therapeutic or prescription diet, or you can make your own CKD-appropriate food. By preparing your own food, you can correct the flaws of therapeutic foods while mimicking the things that they do right.
Above all, cats with chronic kidney disease need to eat.
From Dr. David J. Polzin, DVM, PhD, DACVIM’s “11 guidelines for conservatively treating chronic kidney disease”:
“In many or most dogs and cats with chronic kidney disease, death or euthanasia results directly or indirectly from starvation.”
If possible, make dietary changes while your cat is still interested in eating. Also note that cats often develop an aversion to the food they ate during hospitalization.
Cats in the later stages of kidney failure may feel too sick to try something new. If your cat is refusing to eat, don’t worry about feeding a therapeutic diet. Any food they’re willing to eat is good food.
Choose high-quality protein.
When protein breaks down during digestion, it produces waste. When the kidneys are functioning normally, they filter out this waste and send it on its way into the litter box.
But as your cat loses kidney function, it becomes increasingly difficult to remove these waste products. Instead of passing through your cat’s body, they remain in the bloodstream. This is why BUN levels rise in cats with CKD.
In an attempt to reduce BUN levels, cats with CKD are often given protein-restricted foods.
But in recent years, this practice has become increasingly controversial.
Some experts worry that a protein-restricted diet will lead to severe protein deprivation, decreased muscle mass, and poor physical condition.
Instead of cutting back to 20% or less calories from protein, you may choose to feed moderate levels of highly digestible, low-waste protein from high-quality animal sources.
Choose foods that are low in phosphorus.
As kidney function declines, phosphorus is one of the things that doesn’t get filtered out. As phosphorus builds up in the bloodstream, your cat will start to feel ill and kidney function declines even more quickly.
The best way to counteract this effect is by reducing the amount of phosphorus in your cat’s diet. The ideal diet for a cat with CKD contains less than 0.5% phosphorus on a dry matter basis.
Reduce inflammation with omega-3 fatty acids.
Many cats with kidney disease develop nephritis, or inflammation of the kidneys. Animal-sourced omega-3 fatty acids can reduce that inflammation, helping your cat to feel better for longer.
Increase your cat’s intake of B vitamins.
Because cats with kidney disease urinate so much, they often lose crucial B vitamins in the litter box. Deficiency in B vitamins is associated with loss of appetite and overall poor health.
Supplement with a probiotic.
When bacteria and endotoxins enter the gut, probiotics can help to perform “enteric dialysis”, taking on some of the detoxifying function that the kidneys have lost.
Azodyl is a synergized prebiotic and probiotic supplement designed specifically for cats with kidney disease.
Also Read: Best probiotics for cats
Top 5 Best Foods for Cats with Kidney Disease
Note that all of the foods on this list are canned products. Because cats with kidney disease are prone to dehydration, choosing a high-moisture food is acutely important.
Royal Canin Veterinary Diet Renal Support D Morsels in Gravy Canned Cat Food Review
First 5 Ingredients: Water Sufficient for Processing, Chicken By-Products, Chicken Liver, Pork Liver, Wheat Flour
This gravy-style food from Royal Canin is available by prescription only. It receives consistently positive reviews and doesn’t seem to share the palatability problem that most kidney formulas face.
The food is 30% protein and .44% phosphorus on a dry matter basis, helping to control toxic buildup in the bloodstream.
- Maximized energy density to help keep cats strong and muscular
- Contains omega-3 fatty acids to reduce inflammation
- Low phosphorus levels help your cat to feel better
- Low protein helps to limit uremic toxins
- Many cats prefer a pate-style food
Hill’s Prescription Diet k/d Kidney Care with Chicken Canned Cat Food Review
First 5 Ingredients: Water, Pork Liver, Chicken, Egg Product, Brewers Rice
This food is available by prescription only.
According to Hill’s, this pate style canned cat food is “clinically tested to improve and lengthen the quality of life”. It achieves this by ticking all the standard kidney disease diet boxes.
The phosphorus content of this food is restricted to .49% on a dry matter basis and the protein is 30% on a dry matter basis.
- Controlled phosphorus levels
- Added omega-3 fatty acids for anti-inflammatory effect
- Calorie-dense to support muscle mass
- Highly palatable
- Contains sugar
- Contains caramel color
Hi-Tor Neo Diet For Cats Review
First 5 Ingredients: Sufficient Water for Processing, Meat By-Products, Chicken, Animal Liver, Beef
You might appreciate the convenience and cost advantage of buying a specially formulated non-prescription food.
The phosphorus percentage is about .71% on a dry matter basis, so it’s slightly higher in phosphorus than other formulas. If your cat refuses to eat a lower-phosphorus recipe, you might try this one instead.
In addition to lower-than-average phosphorus, the food has restricted protein content at 36% on a dry matter basis.
- Limited phosphorus
- Some reviews indicate that it’s highly palatable
- Calorie dense to support healthy muscle mass
- Doesn’t contain an omega-3 supplement
- Slightly higher in phosphorus than some other foods
Purina Pro Plan Veterinary Diets NF Kidney Function Advanced Care Formula Canned Cat Food Review
First 5 Ingredients: Water Sufficient For Processing, Beef, Poultry By-Products, Rice, Meat By-Products
Available only with a veterinary prescription, this food from Purina does everything a standard renal diet does. According to customer reviews, this pate-style food is palatable for cats.
On a dry matter basis, the formula is approximately .49% phosphorus and 34% protein.
- Low in phosphorus
- Highly palatable
- Calorie dense to support lean body mass
- Contains carrageenan, which may create inflammation
- No omega-3 supplementation
Blue Natural Veterinary Diet KM Kidney + Mobility Support Canned Cat Food
First 5 Ingredients: Chicken, Chicken Broth, Water, Potatoes, Potato Starch
Although this food is called a “Veterinary Diet”, you can purchase it without a veterinarian’s prescription. In addition to standard renal diet features, this food is formulated with glucosamine and chondroitin for joint health support.
The pate-style food gets mixed taste test results – a notable percentage of reviewers say that their cats didn’t like the food.
Compared to other renal care products, this food has slightly more phosphorus and less protein on a dry matter basis. It’s .77% phosphorus on a dry matter basis and about 28% protein.
- Restricted phosphorus content
- Added omega-3 fatty acids
- Supports joint health
- Contains carrageenan, which may create inflammation
- Higher in phosphorus than some other foods
Royal Canin Veterinary Diet Renal Support S Dry Cat Food Review
First 5 Ingredients: Corn, Chicken Fat, Pork Meal, Brewers Rice, Corn Gluten Meal
High-moisture food is ideal for all cats. It’s even more valuable for those with kidney disease. Cats in renal failure are prone to dehydration and feeding them a water-depleted diet does nothing to help. In fact, feeding your cat a dry diet may have you giving him subcutaneous fluid injections sooner than they’d otherwise be necessary.
Dr. Lisa Pierson puts it into perspective in this quote from an interview conducted by Dr. Karen Becker of Mercola Healthy Pets:
“There’s nothing that frustrates me more than to see cat owners leave their vet’s office with a bag of fluids under one arm and a bag of dry food under the other arm. They’ve been told to feed a water-depleted diet and then stick a needle in their cat’s back to put water into him. That’s pretty nonsensical.”
That said, our top priority is getting your cat to eat. If dry food is all your cat wants to eat, it’s better than nothing. For cats who insist on dry food, his prescription kibble from Royal Canin is be a good option to consider. It has low protein, restricted phosphorus, and supplemental EPA and DHA from fish oil.
Its protein content sits somewhere between 24.5% and 28.8% on a dry matter basis with up to about 0.59% phosphorus on a dry matter basis.
On Chewy, the food has a 4.7 out of 5 star rating and 97% of reviewers say they would recommend the food to a friend.
- Omega-3 fatty acids from fish oil help to reduce inflammation
- Controlled phosphorus helps your cat feel healthier
- Customers report that the square kibble is easy for their senior cats to eat
- Restricted protein helps to lower uremic toxins
- Unlike some other prescription renal diets, the food is free of artificial colors or added sweeteners
- Lacks the moisture your cat needs
- High carbohydrate content
- Slightly more expensive than other dry prescription foods
Helen of FelineCRF.org has created an extraordinary resource for anyone caring for a cat who has CKD. The site contains over a thousand pages of information on almost everything you need to know about feline kidney disease.
Click here to browse FelineCRF.org’s food databases of dry and canned products sold in the US and UK.
As your cat’s kidney disease progresses, it’s likely that you’ll have to pry out their appetite with a variety of foods. These databases may help you to evaluate your options based on CKD-relevant metrics.
In this 34-minute interview, well-known veterinarians Karen Becker and Lisa Pierson explore the causes and treatment of kidney disease in cats. Pierson’s common-sense approach is a calm in the storm of confusion that is chronic kidney disease.
About the author
Mallory Crusta is a writer and adventurecat enthusiast on a mission to make cats’ lives extraordinary. She’s one of the founders of Wildernesscat – a site for happy, healthy, and adventurous cats who are fueled by nature. Visit Wildernesscat for radically natural cat nutrition, home remedies, and lifestyle inspiration.