Grey cat eating from a food bowl

The most important thing with kidney disease is to rehydrate your cat.

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What can I feed my cat with kidney disease?

By Dr. Liz Barton MA, VetMB, MRCVS Veterinarian

Updated on the

Changing your cat's diet and getting them rehydrated are hugely important in helping them with kidney disease.

When it comes to feeding a cat with kidney disease, you'll be advised by a vet to switch to a diet that ensures that the kidneys' work is cut down – so less protein, for example. This should put your cat on the road to recovery, but rehydration will also be necessary, and medication may be too, if your cat is in pain.

How can I help my cat with kidney disease?

The best way to help cats with kidney disease is to reduce the amount of work the kidneys have to do. Cats are obligate carnivores, which means they’re designed to eat almost exclusively protein and fat. The kidneys have the job of excreting waste products from the metabolism of protein, so cats kidneys have to work harder than dogs and humans (who as omnivores have a more varied diet).

Because the kidneys have to work harder, they also age faster, with fibrous tissue being laid down instead of functioning kidney tissue over time. This process is inevitable and irreversible, but cats can actually cope perfectly well even if 75 per cent of their kidneys have aged and become non-functional. By feeding a diet that is reduced in protein, salt and phosphorous, you can reduce the rate at which the kidneys age – senior diets or specialist kidney or renal diets are designed to support kidney function.

There is some evidence that omega-3 fatty acids and antioxidants may also help cats with kidney disease. Increasing water intake will also help your cat to stay hydrated. They will lose more water-soluble vitamins in the urine, so these may need to be supplemented. Certain medications may be recommended by a vet, if there is protein loss through the kidneys or high phosphorous levels.

Is fish good for cats with kidney disease?

Rich, oily fish may be one to avoid because it's high in protein and salt content, but plain white fish will be less work for the kidneys and thus is fine to feed your cat.

How long can cats live with kidney disease?

Almost all cats will have some degree of kidney ageing when they reach their senior years. Yet they can live perfectly normal lives for many years, until only 25 per cent of functioning kidney remains before they become unwell. Some cats will never show ill effects from kidney disease and will pass away from other causes. There are many other causes of kidney disease, some of which affect younger cats.

Is kidney disease painful for cats?

Kidney disease can be painful for cats if there are mineral deposits in the kidneys (kidney stones). Humans with kidney stones describe severe stabbing pains and even back pain associated with kidney problems.

If you see a vet, they may be able to tell if the kidneys are painful for your cat by feeling them in the abdomen during a consultation. They may also give a trial of painkillers and, if your cat seems happier on the medication, it suggests that they were in pain.

Do cats with kidney disease suffer?

Cats with kidney disease may have painful kidneys. The most common complication of kidney disease is dehydration and a build up of toxins in the blood that would normally be cleared by the kidneys. This leads to nausea, vomiting and can even cause ulceration in the mouth. Your cat may go off their food and become very lethargic. Once they are rehydrated and the toxins flushed out of the blood, they usually feel a lot better quite rapidly, though this may require an IV drip.

What food is best for cats with kidney disease?

Food restricted in protein, salt and phosphorous are often required for managing kidney disease. Prescription renal diets may also contain increased omega-3 fatty acids, antioxidants and water-soluble vitamins.

How can I get my cat with kidney disease to eat?

If your cat is not eating, they may become dehydrated rapidly. If they suffer from kidney disease, your cat will lose more water through the urine if the kidneys are not functioning normally. You can try to get them to eat by warming their favourite food so that it smells stronger, and wiping a little on their paw. As they lick if off, it may stimulate their appetite to start eating more. You may have to hand feed them warmed food little and often.

The most important thing is to rehydrate your cat. You may be able to do this by adding water to their wet food, giving them flavoured water (such as the cooled cooking water from boiling chicken or fish), or rehydration fluids specifically designed for cats. If your cat is feeling too unwell to drink enough, they may require IV fluids from the vet, plus additional treatment to stop the feeling of nausea. Sometimes appetite stimulants may have to be given after your cat is rehydrated to get them back into the habit of eating again.

How do you know if your cat is suffering from kidney pain?

If your cat is not eating, is lethargic or stops behaving normally (e.g. by not going outside or playing), then this suggests that feeling unwell is stopping their normal life and they are suffering. If they are yowling, aggressive or moving away – especially when you feel their tummy or back – it may suggest they are suffering from kidney pain.

When should I see a vet?

It is best to see a vet early, if your cat with kidney disease is lethargic and not eating, and especially if they are not drinking. They may also have a ‘skin tent’ where their skin loses elasticity and doesn’t bounce back when pinched up behind the back of the neck. This is a common sign of dehydration. If dehydration is not treated early, toxins will build up in the blood making it harder to correct and sometimes leading to ulceration and vomiting.

What should I ask a vet about the best nutrition plan for a cat with kidney disease?

Talk to a vet and they'll tell you that nutrition to support kidney function is the most important ‘treatment’ for kidney disease. They will talk about what you are currently feeding your cat – it’s also important to discuss any treats that you give your cat, as these may not be good for their kidneys. You and the vet can then discuss different options – from prescription renal diets to senior food to home-made diets.

Prescription diets are specifically formulated for cats with kidney disease, but your cat may not find them palatable. Senior diets are restricted in protein and salt to a certain extent, so may be the next best option. Home-made diets must be formulated with care to ensure they are fully balanced with all the nutrients your cat needs to stay healthy.

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  • rogerp
    Many thanks! The definitive advice for cat owners.
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