Dietary management can’t turn back the clock on kidney disease, but it can make 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.
Look For Foods With Restricted Or High-quality Protein
When dietary protein breaks down during digestion, it produces waste. Healthy kidneys 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.
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 fewer calories from protein, you may choose to feed moderate levels of highly digestible, low-waste protein from high-quality animal sources.
The bottom line is that you want your cat to feel better, not worse. While a protein-restricted diet helps some cats to feel better, it may also lead to muscle wasting and weakness. You’ll have to weigh the costs and benefits of a low-protein diet for your cat.
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.
The Best Cat Food For Kidney Disease Has Relatively Low Sodium Content
Because excessive sodium consumption can increase blood pressure and worsen kidney damage, most renal diets are low in sodium. You’ll also want to avoid any high-sodium treats like luncheon meat and salty cheese.
Reduce Inflammation With Omega-3 Fatty Acids
Many cats with kidney disease develop nephritis or inflammation of the kidneys. Along with other anti-inflammatory supplements, consider omega-3 fatty acids like EPA and DHA. These fatty acids have a well-documented ability to reduce inflammation, helping your cat to feel better.
While humans and other animals can benefit from omega-3 fatty acids derived from plant sources like flaxseed oil, cats can only utilize those found in animal fat. Good sources include various types of fish oil—like salmon oil, menhaden fish oil, and sardine oil—as well as krill oil. You can also consider green-lipped mussels. In addition to being a good source of other omega-3s, they’re the ocean’s most concentrated source of the fatty acid ETA.
While many foods contain sources of these beneficial fatty acids, you may also want to supplement your cat’s diet with a good omega-3 supplement.
Good Foods Give Your Cat Extra 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.
Prescription or therapeutic diets for kidney disease are usually fortified with additional B-complex vitamins. Your veterinarian may also recommend B12 shots to give your cat a boost.
In addition to vitamins in your cat’s diet and subcutaneous injections, consider giving your cat a multivitamin supplement like Vetoquinol Renal K+. Formulated for cats and dogs with kidney disease, this gel contains B-complex vitamins and potassium. Both substances support muscle function and your cat’s nervous system health.
Hydration Is Essential
Because kidney disease causes cats to urinate excessively and lose their appetites, dehydration is common among cats with the condition. Many cats rely on subcutaneous fluid injections to stay hydrated, but there’s more than one way to increase your cat’s water intake.
Wet food is 70% water or more, making it an effortless source of the hydration your cat needs. If you’re currently feeding a dry diet, switching to wet food might give your cat an additional four ounces of water each day. That’s more than you’d give him in a typical fluid injection.
You may still need to give subcutaneous fluids, but feeding a juicy diet will significantly reduce your cat’s risk of severe dehydration.
Should You Feed Your Cat Prescription Food For Kidney Disease?
In summary, decades of research tell us that the best food for cats with CKD is one with the following qualities:
- High caloric density
- High quality or restricted protein
- Low phosphorus levels
- Controlled sodium levels
- Increased B vitamins
- Omega-3 fatty acids
Currently, prescription or therapeutic diets are the only foods that check all of those boxes at once. Frustratingly, those diets often have other not-so-great qualities.
Think high carbohydrate content, added sugar, and potentially low-quality animal by-products.
This gives you a few options.
You can hold your nose over the ugly parts of a therapeutic or prescription diet. You can opt for a non-prescription food that meets one or two of the above criteria. Or you can make CKD-appropriate food at home.
By doing it yourself, you can correct the flaws of therapeutic foods while mimicking the things that they do right.
But you’re also taking a risk—homemade food takes time and it can be hard to get everything right. If you’re going to make homemade cat food for kidney disease, consider working with a veterinary nutritionist to ensure that you don’t miss anything.
Above All, Cats With Chronic Kidney Disease Need To Eat.
From Dr. David J. Polzin, DVM, Ph.D., 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.”
The dietary recommendations above only apply to cats who are still eating. But if the disease has progressed to a point where your cat is no longer interested in food, nutritional rules go out of the window. If your cat is refusing to eat, don’t worry about feeding a therapeutic diet. Any food he’s willing to eat is good food.
Consider Giving Your Cat High-calorie Supplements.
In addition to traditional food, consider giving your cat high-calorie supplements. High-calorie gels and treats help to curb weight loss and keep your cat feeling as well as possible.
Food toppers, broths, and treats can also help. Some cats, especially those with poor dental health, may be willing to eat baby food.
You Might Also Consider Supplementing Your Cat’s Diet With A Probiotic.
When bacteria and endotoxins enter the gut, probiotics may 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 for cats with kidney disease. The supplement contains patented strains of Enterococcus thermophilus, Bifidobacterium longum, and Lactobacillus acidophilus. The three probiotics are synergized with psyllium husk, a source of prebiotic fiber.
While it’s not clear that Azodyl will help, it does show some promise. If you’re not willing to spend over $70 a bottle for the putative benefits of Azodyl, consider supplementing with another probiotic.