Cats with chronic kidney disease have varying symptoms. We have selected the top 5 best supplements for cats with kidney disease for an in depth review. Read on to learn how they can be used to help cats at various stages of the disease.

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A Quick Look At Our Favorites

ProductRatingWhy We Like It
1Zesty Paws Wild Alaskan Salmon OilSupports Kidneys & Overall HealthBuy on Amazon
2AminAvastSupports KidneysBuy on Amazon
3Tomlyn High Calorie Nutritional GelPrevents Weight LossBuy on Amazon
4Vetoquinol EpakitinLowers Phosphate LevelsBuy on Amazon
5Vetoquinol Renal K+Increases PotassiumBuy on Amazon
What We LikeWhat We Don't Like
1
  • Supports kidney function
  • Good for immune system
  • Healthy for skin and coat
  • Omega-3 and omega-6 fatty acids
  • Mixes in with any meal
  • Not for cats with seafood allergies
2
  • Improves appetite
  • Helps to gain or maintain weight
  • Healthy for skin and coat
  • Improves overall mood
  • Supports and prevents
  • Not FDA-approved
3
  • Perfect for fussy eaters
  • Supports weight gain
  • Full of vitamins
  • Omega-3 and omega-6 fatty acids
  • Contains corn syrup
4
  • Reduces phosphates
  • Reduces anemia
  • Manages cholesterol
  • Manages blood pressure
  • High in calcium
  • Not for cats with seafood allergies
5
  • Comes in two flavors
  • Great source of potassium
  • Has cats feeling better quickly
  • Contains sodium
  • Powder is not for cats with seafood allergies
  • Gel is difficult to measure
1 Zesty Paws Wild Alaskan Salmon Oil

Supports Kidneys & Overall Health
Buy on Amazon
2 AminAvast

Supports Kidneys
Buy on Amazon
3 Tomlyn High Calorie Nutritional Gel

Prevents Weight Loss
Buy on Amazon
4 Vetoquinol Epakitin

Lowers Phosphate Levels
Buy on Amazon
5 Vetoquinol Renal K+

Increases Potassium
Buy on Amazon

Best Supplements For Cats With Kidney Disease

Cats with kidney disease can present with a lot of different symptoms, depending on the progression of their renal failure. We have selected the best nutritional supplements that tackle the most common symptoms of kidney failure in cats. Please use this list as a guide in your search for the best supplements for cats with kidney disease. If you can’t find a supplement that is right for you, consider cat treats instead. Before you make any final decisions, please consult with your vet about your cat’s unique needs.

Best Overall Supplement: Zesty Paws Wild Alaskan Salmon Oil

If you were only going to give your cat one supplement for the rest of her life, whether she has kidney disease or not, it should be omega-3 and omega-6 fatty acids. Out of all the supplements on this list, fatty acids are the only one that help 100% of the time. They improve your cat’s skin, make her coat shiny, keep her heart and digestion running smoothly and, most importantly, they support kidney function.

A healthy cat diet contains both omega-3 and omega-6 fatty acids in a ratio of 1 to 5. Meaning there are 5 times more omega-6s than omega-3 fatty acids. Unfortunately, most commercial cat foods only supply the cheaper omega-6, and leave out the omega-3. So whatever condition your cat is in, it is worth supplementing these with a product like Zesty Paws Wild Alaskan Salmon Oil.

Zesty Paws Salmon Oil is liquid and comes in an easy to use bottle dispenser. You can mix it right into your cat’s wet food. Of course, since it’s fish oil, it should not be given to cats that are allergic to fish or seafood. If you notice your cat getting sick or having runny, smelly stools after switching to fish oil, it could be from an allergy. Take her off the supplement and see if her symptoms disappear.

If your cat does tolerate Zesty Paws Salmon Oil, you can rest assured that you are giving her something healthy that helps slow down her kidney disease. For a still healthy cat it will help to prevent issues further down the line.

What We Like
  • Supports kidney function
  • Good for immune system
  • Healthy for skin and coat
  • Omega-3 and omega-6 fatty acids
  • Mixes in with any meal
What We Don't Like
  • Not for cats with seafood allergies

Best Kidney Support Supplement: AminAvast

AminAvast is a kidney support supplement with natural amino acids and peptides that promote healthy renal function. It works on all fronts of the disease, increasing appetite, managing body weight, keeping the skin and coat healthy and improving your cat’s overall mood. AminAvast can also be used as a preventative measure in the early stages of kidney disease.

AminAvast comes in capsules containing a powdered substance. The capsules can be easily opened to sprinkle the powder directly onto your cat’s food. This works best when you use wet food, which is the preferred diet for cats with kidney disease. It can be used in conjunction with other treatments for cats with kidney disease, though I advise you to always consult with your vet first.

There has been some controversy surrounding AminAvast, which was previously sold under the name RenAvast. RenAvast was banned by the FDA in 2015 for making false (unproven) claims about its health benefits for dogs and cats with kidney disease. The company has since renamed and rebranded the product, but no apparent changes were made to its composition.

Regardless of this controversy and the lack of scientific proof of its efficacy, there is a ton of anecdotal evidence out there that shows AminAvast has improved, lengthened and even saved the lives of many cats with kidney disease. And vets swear by it. Ask your vet if AminAvast is a good supplement for your cat and make your decision accordingly.

What We Like
  • Improves appetite
  • Helps to gain or maintain weight
  • Healthy for skin and coat
  • Improves overall mood
  • Supports and prevents
What We Don't Like
  • Not FDA-approved

Best Weight Management Supplement: Tomlyn High Calorie Nutritional Gel

Cats with kidney disease can have trouble maintaining a healthy weight. Between their lack of appetite and compromised ability to retain nutrients, it is an uphill battle. You can support your renal failure cat by giving her a high calorie nutritional gel, often referred to as nutri-cal.

Tomlyn High Calorie Nutritional Gel contains a large dose of all the vitamins your cat needs on a daily basis. It is supplemented with omega-3 and omega-6 fatty acids, which directly support her kidney function and digestive system.

It is worth mentioning that Tomlyn Nutri-Cal, and most other nutri-cals, get their calorie content from corn syrup. This is a great, sugary fattener and, as such, should not be given to cats that are already overweight, (pre-)diabetic or suffering from dental issues. To prevent your cat from going down this path, I recommend using a nutri-cal only on days that she is extra finicky about her food.

What We Like
  • Perfect for fussy eaters
  • Supports weight gain
  • Full of vitamins
  • Omega-3 and omega-6 fatty acids
What We Don't Like
  • Contains corn syrup

Best Phosphate Binding Supplement: Vetoquinol Epakitin

Phosphorus build-up in the blood of cats with kidney disease can lead to loss of appetite and anemia. If your cat’s blood test shows that her phosphate levels are increased, you are wise to give her a phosphate binding supplement. This will filter the excess phosphorus from her system and improve her overall health.

Vetoquinol Epakitin is a phosphate binder for cats with kidney disease made with chitosan. Chitosan is a complex sugar that not only facilitates the discharge of phosphorus from the blood, but also helps to manage cholesterol, blood pressure and sleep. As a result, your cat’s BUN and creatinine levels will drop, effectively slowing down the progression of her kidney disease.

Chitosan is extracted from the shells of shrimp and other crustaceans, so beware if your cat suffers from seafood allergies! Another word of caution should be given about the fact that Epakitin is calcium-based. If your cat’s calcium levels are already high, don’t give her this.

In all other cases, consult with your vet and have them test your cat’s blood regularly. As soon as her phosphorus levels are back to normal, stop giving the supplement.

What We Like
  • Reduces phosphates
  • Reduces anemia
  • Manages cholesterol
  • Manages blood pressure
What We Don't Like
  • High in calcium
  • Not for cats with seafood allergies

Best Potassium Supplement: Vetoquinol Renal K+

If your renal failure cat is losing weight to a point where you can’t manage it with food alone, a potassium supplement can do wonders. Vetoquinol Renal K+ contains a high dose of concentrated potassium that will have your cat feeling better in a matter of days.

Vetoquinol Renal K+ for cats with kidney disease comes in a maple flavored gel or a chicken and fish flavored powder. So you have options, if your cat doesn’t like maple or is perhaps allergic to seafood. Overall, cats do seem to prefer the powder over the gel. The powder is also easier to measure for accurate dosage.

The only real downside to Vetoquinol Renal K+ is the fact that it contains sodium, or salt. Some cats with kidney disease, mainly those that also suffer from high blood pressure or obesity, can already have too much sodium in their system.

This underlines again the need to consult with your vet before starting your cat on any supplements or diets. Whatever you give her, it should match up with her actual needs. And those needs change over time, which is what you want. If a supplement does what it needs to, it will eventually become unnecessary.

What We Like
  • Comes in two flavors
  • Great source of potassium
  • Has cats feeling better quickly
What We Don't Like
  • Contains sodium
  • Powder is not for cats with seafood allergies
  • Gel is difficult to measure

Our Choice For Best Supplements For Cats With Kidney Disease: Zesty Paws Wild Alaskan Salmon Oil

Since kidney disease is such a slow progressing condition that attacks on multiple fronts, it can become difficult to manage. Especially in its later stages. Zesty Paws Wild Alaskan Salmon Oil, and fish oil in general, is a great and safe way to support your cat’s kidney function, even if she isn’t in renal failure yet. With Zesty Paws Salmon Oil you can battle the disease at the source, instead of running after it and merely controlling symptoms. That is why it is our number 1 in the best supplements for cats with kidney disease.


Chronic Kidney Disease In Cats

Chronic renal failure, or chronic kidney disease, is one of the leading causes of death among domestic cats. The cause of the disease is often unknown. Not knowing the cause makes it difficult to treat beyond merely managing the symptoms as they pop up.

As pet owners we usually don’t like just waiting around to see if our cat will get worse, or stay as she is. Ideally, we would completely heal her, but unfortunately that is not an option for cats with kidney disease. The best we can do is to improve their quality of life and stall progression of the disease as long as we can.

One way to do that is through a healthy and balanced diet tailored to your cat’s needs as a kidney patient. Controversies do exist around what is the best diet for cats with kidney disease, though. On top of that, chronic kidney disease tends to make picky eaters out of cats, so she may not leave you much choice in that area.

Luckily, you won’t have to compromise on your fussy feline’s health over cat food, whether it’s wet or dry. Nutritional and mineral supplements are a great way to balance out your cat’s diet and make sure she has everything she needs to maintain her health. Ask your vet to do a full blood panel to see exactly what your cat has a lack, or an excess, of.

Nutritional Challenges For A Renal Failure Cat

Not all nutritional supplements are made equal. And especially with a kidney disease cat, you want to be extra careful not to introduce any unnecessary or harmful substances into her system. Always consult with your vet before starting your cat on supplements. A simple blood test can tell you exactly what areas your cat needs help in.

Let’s go over the main challenges facing cats with kidney disease and how specific supplements can help to reduce these. If you want a more in-depth look at renal failure in cats, check out our full guide on Chronic Kidney Disease In Cats.

Phosphorus

As the kidneys get damaged and their function diminishes, more waste products will remain in your cat’s bloodstream. Phosphorus is usually the first substance that rises to levels high enough to cause visible signs of kidney disease, mainly a loss of appetite or fussy eating habits.

Decreasing the amount of phosphorus in your cat’s system can help her to regain her appetite. This in turn will encourage her to eat more, so she can maintain a healthy weight and get all the nutrients she needs to support her kidneys.

Potassium

All cats need potassium. It works to support muscle strength and nerve function in the whole body. Unfortunately, about 30% of cats with kidney disease have low potassium levels. It simply leaks out of their system through vomiting and increased urination. If your cat has a potassium deficiency, a good supplement can really turn things around and increase her lifespan significantly.

Beautiful cat laying on its side

Calcium

Calcium can both be elevated, or decreased, in cats with kidney disease. Too much calcium (hypercalcemia) means the kidneys aren’t able to filter it from the blood. This causes gastric upset and vomiting. It can also lead to urinary infections and the formation of urinary crystals. Too little calcium (hypocalcemia) means your cat’s kidneys can’t retain enough of it in the blood. Hypocalcemia leads to brittle bones that break easily. 

Vitamins

Vitamins are essential for your cat’s overall health. Vitamin A helps support eyesight, muscles and nerves. Vitamin B is a real powerhouse as it regulates the immune system, the nervous system and the gastrointestinal system. Vitamin D is necessary to absorb calcium from the digestive tract and control calcium storage in the bones.

If you supply your cat with the right combination of vitamins, you can do a lot to counteract the symptoms of kidney disease. This underlines the need for regular blood tests. You can test if your treatment is working and adjust where necessary along the way.

Fatty Acids

Fatty acids are the only supplement that I would advise giving to your cat regardless of her blood work. Omega-3 directly works to slow the progression of kidney disease by decreasing the production of compounds that contribute to kidney infections and deterioration. It also helps to retain good proteins in the blood.

Omega-6 fatty acids are also important. However, most cat foods already contain these in a healthy amount. Consult with your vet to see if your cat needs a supplement of omega-6.