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

Why Does My Cat Kick Litter Out of the Box? 5 Vet-Reviewed Reasons

Cat owners all over the world are familiar with that awful feeling of stepping barefoot on small litter pebbles, which is usually followed...

Oriental Longhair Cat Breed: Info, Pictures, Temperament & More

You might be smitten by the majestic look of the elvish Oriental Longhair. If they caught your eye, you probably want to learn...

Ussuri Cat Breed Info: Pictures, Traits & Facts

The Ussuri is a naturally occurring hybrid that originated from Russia in the Amur River region. There is very little information about this...

Can Cats Drink Tea? Vet-Approved Nutrition Advice

Tea is a common beverage in many households, and it’s not uncommon to wonder if you can give some to your cat. It’s...

More related

Can Cats Eat Flour? Our Vet Answers

Your cat probably isn’t sticking their head into a bag of flour in search of a meal. But if you have any concerns...

Is Alstroemeria Toxic to Cats? Vet-Approved Advice

If your cat just ate some of your Peruvian Lily or rubbed on the petals you may be panicking. Although The ASPCA lists...

Creating Outdoor Spaces for Indoor Cats: Dr Karyn’s Catio (with Video)

Hi, I’m Dr. Karyn! Read my introduction to learn more about me and meet my five hilarious cats: Clutch, Cyril, Alex, Zelda, and...

What to Do With Cats After a Natural Disaster? 8 Post Hurricane Tips (Vet Reviewed)

Living through a natural disaster like a hurricane takes resilience, tenacity, and planning. The powerful storms fundamentally alter landscapes and lives before moving...

Keep reading

12 Vet-Approved Tips That New Cat Parents Should Know About Feline Health

If you’ve recently adopted a cat, you may wonder how to ensure your new companion stays healthy so you can enjoy years of happiness together. There’s plenty of feline health information for new cat parents to become familiar with, but...

veterinarian doctor holds cat

Why Does My Cat Purr When They’re Asleep? Vet-Reviewed Feline Behavior

Is there anything sweeter than seeing a cat curled up in a cozy nook, purring in their sleep? We can’t think of much that beats it. But if you’ve ever wondered why cats purr in their sleep—and if they’re really...

cat under porch sleeping

Why Does My Cat Meow When I Pick Her Up? 4 Common Reasons (Vet-Verified)

Cats may meow for all sorts of reasons when you pick them up. In most cases, though, it is a sign of protest. Cats typically do not meow when they want to be picked up, but they may meow when...

young womn carrying her cat outdoors

Can Cats Eat Honey? Vet-Reviewed Facts & FAQ

If you love eating honey yourself, you probably know that it has antibacterial properties and is packed full of antioxidants and vitamins. It’s good for us humans, but does that mean it could be good for our cats too? So...

Can Cats Eat Honey

How to Make Dry Cat Foods Soft: 6 Vet-Approved Methods That Work

Some owners prefer to feed their cats dry food, whether as a solitary source of food or in addition to wet food meals. Because kibble is dehydrated, cats on a kibble diet should be drinking water to prevent dehydration. However,...

orange cat eating wet food

10 Best Dry Cat Foods in Canada in 2025 – Reviews & Top Picks

If you have a new cat and are looking for the best dry food or you need to switch your current cat’s food, you know that there are so many products out there! If you live in Canada, you also...

persian cat eating dry food

Nutrisca Cat Food Review of 2025: Recalls, Pros & Cons

Review Summary Your cat food choice is one of the most important decisions you will need to make concerning your pet, but with so many choices available, it can be difficult to know which brands are healthy and tasty. Nutrisca...

Nutrisca Cat Food Review

14 Ways to Provide Mental Stimulation for Cats: Vet-Reviewed Recommendations

Cats are perceived as lazy creatures. It’s true that they enjoy lounging around and taking naps, but that doesn’t mean they don’t need mental stimulation too. A bored cat can become destructive or obese or develop other behavioral problems. That’s...

Cat playing with a toy mouse on a cat scratch stand