The truth about milk and its effects on cats’ kidneys

If you come from a home with a cat, you will find out that your cat is fed milk more than other foods.

This is from the ready-fixated idea that cats love milk.

TV shows also have contributed to the idea that cats should drink milk. 

Unfortunately, cats cannot talk. They would have told you that milk gives them stomach upset and they drink milk because they are attracted by the fat in the milk. 

Unfortunately, adult cats are lactose intolerant. They develop intolerance once they stop breastfeeding.

Therefore, Milk is a bad supplement for adult cats. If the cat has a kidney issue, then milk will make it worse.

Is milk harmful to cats?

Kittens feed on their mother’s milk

Kittens feed on their mother’s milk for the first 6-8 weeks of their lives. After 8-10 weeks, the cat is already fully transitioned to solid food.

At this point, the cat loses its ability to digest milk. This is because adult cats have low levels of the enzyme Lactase that digests lactose which is the largest component of cow’s milk. 

When you give your adult cat cow’s milk, it ends up having a stomach upset and diarrhea. It can happen even with milk is mixed with water too.

Under extreme conditions, your cat might develop obesity due to the high level of fat in the milk. 

How to Avoid cat diarrhea due to cow’s milk for cats?

cat drinking cow milk from a basket

To avoid this, there is a specially formulated milk for cats. This milk does not have a high level of fat and lactose.

However, you still need to feed your cat in moderation. The manufactured milk can still cause stomach upset if you overfeed your cat.

You can add some water to the milk. 

Although the manufactured cat’s milk is better than cow’s milk, there are instances where you should avoid feeding your cat any milk. For instance, your cat has some underlying health conditions.

The common occasion when you should not feed your cat milk is discussed below. 

Is milk bad for a cat’s kidney?

Milk does not affect the kidneys of a healthy cat. However, if a cat has certain kidney conditions, it is better to refrain from giving your cat milk. You can consult your veterinary nutritionist to find out if your cat can feed on any form of milk. 

There are some common kidney diseases where your vet will warn you against feeding your cat milk. These diseases include;

  • Chronic kidney disease and
  • Renal Disease

These two kidney diseases have almost the same dietary restrictions. Consult with a Vet to know what not to feed your cat if they have either of the two diseases. 

How does milk affect cats with kidney problems?

old cat drinking milk

The kidney is responsible for filtering waste from the body.

If there is any issue with the cat’s kidney, it will have a hard time removing waste from the body.

For this reason, ensure you take your cat to a vet to know if your cat has any issues. Some of the most common kidney diseases in cats are;

  • Chronic Kidney Disease(CKD)

A cat with Chronic Kidney Disease cannot filter waste as expected. If your cat has CKD, your vet will advise you on the proper diet for your cat.

Some of the foods that you will be warned against giving your cat are milk. 

Phosphates which are mostly associated with proteins increase the progression of CKD.

Since milk has a high level of phosphate, avoid giving it to your cat at all costs. 

  • Renal Disease

Diets with high sodium and fat level are not suitable for cats with renal disease.

Examples of these foods are milk, cheese, and all dairy products. 

Can milk cause urinary problems in cats?

Yes. Milk has a high level of calcium and fats. This might cause large deposits of minerals which might end up causing your cat to develop kidney stones and bladder stones. 

Can milk cause crystals in cats?

several cats drinking special milks designed for cats only

Struvite crystals are some of the most common crystals found in cats.

They are mostly found in cats that have urinary infections. The crystals may go for a long time without being detected.

However, in extreme conditions, your cat might start showing some symptoms such as loss of appetite, and pain when passing out urine. 

The main cause of Struvite crystals is not known. However, it is associated with the presence of Feline Lower Urinary Track Disease (FLUTD).

This disease is mainly associated with phosphate, magnesium, and  Ammonium. And as we already know, milk has a high level of phosphate.

There it might play a huge part in giving your cat crystals.

What can I feed my cat with kidney disease?

Before designing a meal plan for your cat, ensure you consult with your veterinary nutritionist on what foods you should give your infected cat.

Some of the dietary tips you might receive from your vet are;

  • Don’t feed your cat milk. Adult cats have a hard time digesting lactose which is at a high level in milk. If your cat has kidney disease, feeding it milk will increase the progression of the disease. Check the special type of milk for cats which has a low level of fats, lactose, sodium, phosphate and Ammonium. 
  • Give your cat more water. Although cats are not natural water drinkers, create a routine where your cat will enjoy drinking water. 
  • Feed your special cat diets. There are some foods specifically formulated for cats with kidney diseases. Some of these foods include;
  1. Hill’s Prescription Diet Food
  2.  Purina Pro Plan 
  3. Royal Canin Veterinary Diet 

These are just a few dietary foods for cats with kidney disease. Consult with your Vet to find the best food for your cat. 


Although people are acquitted of giving their cats milk, milk is very bad for adult cats. Milk will harm your cat’s life if it has a slight problem with its kidney.

Frequently Asked Questions

What foods cause kidney failure in cats?

Mostly feeding dry food over a longer period may cause stress in your cat’s kidney.

What to do if the cat drinks milk?

Carefully watch whether your cat is vomiting or having any signs of stress.

If it seems so, contact your personal vet for relevant medical advice.

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Amelia Kteylor

Amelia Kteylor, DVM, attended the University of Georgia. She is a cat expert with 20 years of experiences in field. She has a passion as a writer and editor for pet publishing industry too. Amelia contributes to numerous pet magazines in the areas of pet health and groom. Further, she volunteered in cat rescue centers in her leisure time.

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