Kidney diets (also called “renal diets”) are probably one of the first things that your vet will suggest to support your cat if they are diagnosed with kidney disease. These diets are made by specialist manufacturers and can be more difficult and expensive to find than regular diets. Plus, changing a cat’s food over can be a tricky business. Many are fussy about new foods, and can sometimes get an upset stomach if the food is changed over too quickly. 

So why is your vet so keen to recommend one of these foods? Let’s have a look at the evidence!

A Better Life

The first reason to feed our cats with kidney disease a special diet is because it will help them to feel better! Studies have shown that these diets can reduce the symptoms of kidney disease; meaning our cats get to enjoy a better quality of life. 

In particular, they:

  • Relieve your cat’s nausea
  • Improve your cat’s energy levels
  • Slow or prevent your cat’s weight loss

They will also reduce the number of “flare-ups” that your cat has. Periods of time where their symptoms become more intense, and they may need extra medical treatment to improve the situation. This means that your cat can get on with living their life, even when their kidneys are not working as well as they used to. 

A Longer Life

Many different studies have shown that feeding cats with kidney disease a special diet will help them to live longer. These diets have lower levels in the parts of the diet that our cats’ kidneys have difficulty dealing with, such as phosphorus and sodium. This means that feeding these diets will relieve some of the strain on your cat’s kidneys, and allow them to work better for longer. 

Cats may also find it easier to maintain their body weight on these special diets, as they feel better and are therefore more likely to eat properly. Low body weight is linked to shorter survival times in cats with kidney disease. So keeping them in good shape is very important. 

Less Medication

Kidney disease may cause other problems in your cat’s body, including high blood pressure, increased phosphate in the blood, and increased protein levels in the urine. Cats who eat a special diet may find that they need fewer medications to help control these side-effects of their kidney disease. 

 These diets may help to reduce:

  • Phosphate levels in the blood
  • Blood pressure
  • Protein loss through the kidney

Your vet will monitor your pet regularly for these issues if they have been diagnosed with kidney disease. They will recommend any treatment to you if they are found. Your cat may still need medication in time, even if they are on a special diet. But it may take longer for this to be necessary, and they may need a lower dose than they otherwise would have.  

Introducing The Food 

None of these benefits of feeding kidney food mean that it is any easier to persuade your cat to eat their new food. You will need to slowly introduce a kidney diet alongside their existing food. And then start to decrease the amount of their regular diet that you are offering, until they are just eating the kidney food. Try to avoid mixing the two diets together, as this can make cats think that the new food is “contaminating” the old one, which can put them off eating it. 

It usually takes a couple of weeks to go through this process, but it may be longer for some cats. If you are finding it hard to get them to accept it, try warming up the new food. This can make it smell more appealing, which may encourage some cats to eat it. 

If you are struggling to encourage your cat to eat the new food, do speak to your vet for advice. They may be able to offer further suggestions. There are also some medications that can help to improve your cat’s appetite.


Special diets are one of the most important treatments that we have for kidney disease in cats, and can help them to live longer, happier lives. It may take some time for your cat to get used to eating the new food. But it is worth persevering, as the long-term benefits are worth the short-term effort. 

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