Get

In Your Inbox

Catster is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

Are Cats Lactose Intolerant? Vet-Reviewed Facts & FAQ

A cat with milk bottles

Cats are infamous for their love for milk. However, it turns out that cats might be lactose intolerant. But how true is that claim?

Unfortunately, it is true: Most cats are lactose intolerant. Lactose intolerance is the inability to digest the primary sugar in milk and other dairy substances, such as cheese.

Lactose-intolerant cats suffer from stomach cramps, among a host of other digestive issues, when they ingest dairy products. The vast majority of cats are lactose intolerant.

divider cat faces oct 2024

Why Are Cats Lactose Intolerant?

cat on a wooden table_HartmutStein, Pixabay
Photo Credit: HartmutStein, Pixabay

Lactose is the primary carbohydrate in milk. It is a disaccharide sugar consisting of glucose and galactose and is found in all types of milk in varying percentages.

Like all other baby mammals, kittens are born with the innate ability to process lactose, thanks to the enzyme lactase. This enzyme splits lactose into simple sugars, allowing kittens to digest milk without any trouble. It is crucial for kittens to have this ability since they are completely dependent on their mama’s milk for survival during the first few weeks of their lives.

As with all other mammals, cats lose the ability to break down lactose as they grow older because their bodies produce less and less of the lactase enzyme over time. By the time kittens are 6 months old, they usually have all but lost the ability to break down lactose. Once the body stops producing the enzyme lactase, it stops for good.

When a lactose-intolerant cat drinks milk, the unprocessed lactose draws lots of water into the digestive tract, and the cat’s gut bacteria begin to ferment the undigested sugars. That is what causes signs of an upset stomach, including bloating, cramping, gas, and diarrhea, within 8—12 hours of drinking milk.

Note that lactose intolerance is not a type of food allergy. With food allergies, the cat’s immune system views the substance as a foreign material, prompting an attack. That reaction becomes more severe with each repeated exposure to the allergen.

However, with lactose intolerance, the signs only last as long as lactose remains in the system, ceasing when the sugar is expelled from the cat’s body.

divider cat paws oct 2024

Can Kittens Ingest Dairy?

little kitten sitting by a bowl of milk
Image Credit: Impact Photography, Shutterstock

As mentioned, kittens produce the enzyme lactase to digest the lactose in their mother’s milk. Does it mean that it is okay for them to drink cow’s milk or ingest other types of dairy products?

The answer is no. Cow’s milk, as well as other dairy products, can still harm a kitten. Lactose appears in varying percentages in different types of milk. Also, the nutritional profile of each species’ milk is very different. A kitten’s digestive tract is designed to process cat milk, not any other milk. As such, avoid feeding cow’s milk and dairy products to your kitty.

divider cat paw scratch oct 2024

Conclusion

Many cats love the taste of milk and dairy products for some reason and will consume them without a second thought. But these furballs are usually lactose intolerant, and their bodies will not tolerate milk. Therefore, keep it away from them.


Featured Image Credit: Ben Queenborough, Shutterstock

Want content like this delivered to you?

Sign Up For Our Newsletter

News, insights, expert advice, and everything cat

* By submitting, you agree to our Terms & Conditions and Privacy & Cookies Policy.

How useful was this post?

Click on a star to rate (you can leave written feedback after clicking submit)

Help us improve Catster for pet parents!

Your feedback really matters.

What did you like about this post? Also how can we improve it?

Join the conversation

Leave a Reply

You’re very welcome to leave a comment or question. Please know that all comments must meet our community guidelines, and your email address will NOT be published. Let’s have a positive and constructive conversation.

Talk With A Vet Online

Peace of mind,
anywhere, anytime

Affordable vet advice

Is Advantage 2 Safe for Cats? Medication, Dosage & Usage

Fleas are pesky pests. They live on our dogs and cats and can cause various problems: intense itching, tapeworms, and anemia, to name...

Are Ragdoll Cats Hypoallergenic? Breed Facts & Allergies Tips

Cute, cuddly, and super calm, Ragdoll cats make excellent kitty companions for almost anyone. With fluffy fur and a docile personality, the Ragdoll...

Why Your Older Cat Is Not Using the Litter Box (7 Likely Reasons)

It can be a bit frustrating when your cat uses the bathroom outside the litter box, but it’s not uncommon for older cats...

Why Do Cats Like to Sit on Plastic Bags? 5 Interesting Reasons & Vet-Reviewed Safety Tips

It happens almost every time you go to the grocery store: You arrive home with plastic bags in hand and are greeted happily...

More related

“Play Him Off, Keyboard Cat!” Why Did It Go So Viral?

Most of the time, meme culture moves too fast to perceive. If you want to feel old, listen to this: Steamed Hams, the...

Can Cats Eat Bonito Flakes? Vet-Approved Facts & Benefits

With dozens of cat treats available, it can be hard to know what’s good for your cat. After all, most cat treats try...

Why Do Cats Stare at Nothing? 4 Possible Reasons

Experienced cat owners know that no matter how much we bond with and learn about our pets, there will always be at least...

Litter Genie vs LitterLocker: Our 2025 Review & Comparison

Litter box odor can feel like a never-ending battle for cat owners. Whether it’s the box itself or the odors the mess we...

Keep reading

Why Does My Cat Put Its Paw on My Face? 5 Vet-Verified Reasons & What It Means

As a cat lover, you may appreciate that your cat shows you attention by putting its paw on your face. Cats are strange creatures, and they do things for their own reasons, which most humans can’t even begin to understand....

cats paw on mans face

My Cat Ate a Chicken Bone! Here’s What to Do (Vet Answer)

For most cats, a chicken bone is a temptation that’s hard to resist! Wild cats often consume their prey without removing the bones, but domesticated cats are unaccustomed to eating wild cat meals. So can cats eat chicken bones? Whether...

My Cat Ate a Chicken Bone

Can Cats Eat Wheatgrass? Vet-Reviewed Benefits & Facts

If you have a dog, chances are you’re used to asking them what they have in their mouths. On the other hand, cats can be a little fussier about what they eat, but some nibble the edges of plant leaves...

Can Cats Eat Wheatgrass

Does My Indoor Cat Need a Rabies Shot? Vet-Reviewed Facts & FAQ

Like humans, cats are susceptible to several diseases that can be deadly. There’s good news, however, as there are vaccinations for most of the worst cat diseases. When vaccinated, your cat’s immune system will be prepared to handle all of...

Balinese cat lying on sofa at home

Cat Airplane Ears: 4 Vet-Verified Reasons Why Cats Do This, Facts & FAQ

Cats are known for their quirky behaviors, but one that continues to baffle pet owners is when they have “airplane ears.” This seemingly strange behavior does have a purpose, and it’s not necessarily a good thing when your cat has...

Cat laying on the grass with airplane ears

Newborn Kitten Care 101: Guide & Care Sheet for a Healthy Kitty

The thought of looking after an adorable newborn kitten can be appealing, but it’s incredibly hard work! Whether you find yourself helping your cat support her kittens or fostering a kitten that’s been abandoned, kittens require round-the-clock care to grow...

A small newborn kitten in the palm of a hand

How Often Should I Brush My Cat? Vet Approved Advice

If you’re a cat parent, you’re familiar with the lovely moments you spend brushing your cat while they purr away contentedly. Or, if your cat is less cooperative, you’re no stranger to indignant paw swipes. Although brushing may not be...

woman brushing the Persian cat

My Cat Is Limping & Not Eating, What Do I Do? Vet-Verified Tips & FAQ

A limp can be a sign of minor injury to the paw that will heal on its own in a few days. But it can also be a sign of more serious conditions like broken bones, heart conditions, and even...

red tabby cat in pain walking limping on grass outdoor