Skip to Content
Did you know that most cats are lactose intolerant? It’s true. While they’ll happily lap up the white stuff if you present it to them, for many cats this “treat” will result in stomach cramps and that’s no fun. An article in Science Focus debunks the popular myth of the kitty with the saucer of milk by describing the biology of cats. “Like all infant mammals, kittens are born able to digest the main sugar in milk, lactose. This sugar is a very valuable source of energy for young animals, but soon after they are weaned, the enzyme that enables them to digest it, lactase, begins to disappear from the gut. When an adult cat drinks milk, the indigestible lactose in its gut may start to ferment, causing a stomach upset." Turns out, this is lactose intolerance is perfectly normal in both humans and cats. According to Linda P. Case, MS, adjunct assistant professor at the University of Illinois College of Veterinary Medicine and author of The Cat: Its Behavior, Nutrition, and Health…. "But as we grow up, it’s normal for people and cats to begin producing less lactase. Less lactase means less ability to digest lactose. The result may eventually be lactose intolerance. When a lactose-intolerant cat drinks milk, the undigested lactose passes through the intestinal tract, drawing water with it, according to the Cornell University College of Veterinary Medicine's website. Bacteria in the colon also ferment the undigested sugars, producing volatile fatty acids. All that activity might lead to an upset tummy and induce vomiting." (Source) Another symptom is diarrhea. If your cat is lactose intolerant, you'll know within eight to 12 hours because they'll exhibit the symptoms of diarrhea, vomiting, or upset tummy.
What About Cats Who LOVE Their Milk?
While the majority of cats are lactose intolerant, there are those who love their milk. They may rub against your leg when you pull the milk carton out of the fridge or demand your cereal milk. Not every cat gets sick from milk and if yours is one of the milk loving kitties, then you can give an occasional treat.
Although if your cat REALLY loves milk and seems to handle it, there’s little harm in the occasional treat. “If you want to give your cat milk, the safest bet is to purchase special lactose-free cat milk from your supermarket or pet store. Bear in mind that milk contains calories (water has none) so do keep it minimal. Obesity has serious health implications for cats.” (Source) Better treats for cats include small tastes of tuna or other animal-derived protein. As you may know, cats have specific nutritional protein-based requirements that their bodies are better designed to handle than milk.
Are you surprised by that most cats are lactose intolerant? Many people are surprised. It's always a good idea discuss your pet's diet with your veterinarian to make sure you're not inadvertently feeding your cat something that can make her sick. Your family veterinarian can make recommendations for the best cat food for your cat.
Back to top
If you’ve ever read children’s books where there’s a cat, you’re probably wondering, “Can cats drink milk?” The age-old myth that milk and cats go hand-in-hand has officially been debunked by veterinarians and cat experts. Regardless of how tasty milk may be to your cat, this is bad news for their stomach and digestive system. As it turns out, most cats are lactose intolerant.
Is milk bad for cats?
Just like humans, some cats can’t digest lactose, a milk sugar that’s found in dairy. The only time in a cat’s life when its body actually has enough of the enzyme lactase to properly digest lactose is at birth and during its early years of life. This is so the cat can feed off of its mother’s milk. After that, less and less lactase is produced, resulting in potentially increased digestive complications.
“Even though some cats can tolerate milk and seem to enjoy it, cow’s milk just isn’t good for cats,” says Dr. Gary Richter, a veterinary health expert with Rover. “Cats don’t need dairy milk, and the potential problems outweigh the potential benefits.” Here are some other signs that your cat is trying to tell you something.
What happens when cats drink milk?
“[When a cat drinks milk] undigested lactose will stay in their intestines rather than passing into the bloodstream, and end up fermenting,” says Dr. Richter. “Whole, 2 percent, and skim cow’s milk can also add unhealthy amounts of fat to your cat’s diet.” Since cats don’t have the enzyme necessary for digesting lactose, drinking milk can lead to gastrointestinal issues such as an upset stomach, diarrhea, vomiting, loss of appetite and weight, abdominal pain and discomfort, and cause behavior changes such as increased scratching.
Again, just like humans, some cats don’t have a problem digesting milk. Regardless, most veterinarians suggest other alternatives since cow’s milk has no nutritional benefits for cats.
“Cats feed on their mother’s milk after they are born. The only time in a cat’s life when their body has enough of the enzyme lactase to properly digest lactose is at birth and during the first 12 weeks of their life,” says Dr. Richter. “Once their teeth come in, kittens will wean off their mother’s milk and begin eating food.”
What should your cat be drinking instead?
Cats need plenty of water,” Leasa Greer, the Manager of Nutrition & Regulatory Affairs at Solid Gold Pet, told Reader’s Digest. “Water is incredibly important for promoting optimal organ function in cats. A great way to make sure your cat is getting enough water is by feeding him/her wet canned food. Cats are generally less keen on drinking water, so wet food is great for keeping cats hydrated.” Now that you know the answer to the question of, “Can cats drink milk,” is “no,” make sure you avoid making these other dangerous mistakes that cat owners make.
Signs Your Cat Is Secretly Mad at You
Cat Facts You Never Knew
The Cutest Cat Breeds as Kittens
Originally Published: October 04, 2019
Yes, adult cats can technically drink milk. Just because cats can drink milk doesn’t mean they should, though.
Cats should only get milk as a rare treat as opposed to an everyday item. Adult cats are drawn to the creamy allure of milk, but only some can drink and digest it.
What may seem like a harmless treat can cause gastrointestinal distress for your feline companion. Our experts explain why cats crave milk and how to safely feed it to them to avoid digestive upset.
Can You Give Kittens Milk?
Yes. Kittens drink their mother’s milk, a kitten milk replacer or kitten milk formula for their first four to five weeks.
How long does a kitten need milk? Their mother can begin to wean them off as early as four weeks. Note that other kinds of milk, like cow milk, soy milk, almond milk and goat milk are unsuitable for kittens and may give them diarrhea or cause dehydration.
Typically, kittens are eating solid foods by 8 to 10 weeks old. Although kittens can drink their mother’s milk, many cats lose the ability to process it after being weaned.
According to Purina Nutritionist Karina Carbo-Johnson, MS, “When cats are weaned, they most likely lose their ability to digest lactose, the main sugar found in milk, due to eating solid foods. However, some cats can digest lactose and other sugars found in milk into adulthood and potentially for life.”
Is Milk Good for Cats?
Not really. When you think of giving cats milk, you’re probably thinking of cow’s milk. This type of milk isn’t healthy for most cats, especially if it’s taking the place of a balanced meal. “Cow’s milk does not supply all the essential nutrients needed to support your cat’s health,” says Carbo-Johnson.
Whole, two percent and skim cow’s milk can also add unhealthy amounts of fat to your cat’s diet. According to Carbo-Johnson, “Added fats can cause unnecessary weight gain and cause an upset stomach.”
Plus, the high amount of lactose found in cow’s milk is usually too much for a cat’s system to tolerate and can lead to diarrhea, bloating and flatulence. Purina nutritionist Lori Mintle adds, “Loose stool can indicate lactose intolerance in your cat.”
What Do Cats Drink Instead of Milk?
All animals need water, including your cat. Since cats don’t always drink enough water, they may get dehydrated.
If that’s the case with your cat, adding wet cat food to their diet can contribute to their daily total water intake. Some cats prefer moving water rather than drinking from a bowl, so using a cat fountain may encourage them to drink more.
Why Do Adult Cats Crave Milk?
Even if your cat is an adult, they may still crave milk. Like people, cats associate certain flavors and scents with positive memories, so milk is like comfort food for them. Although your cat shouldn’t drink milk for a meal, you can satisfy their cravings with foods prepared with milk as an ingredient.
Can I Pour Milk on My Cat’s Favorite Food?
No. It may seem like a good idea, but this may cause GI problems. “Pouring milk on your cat’s food may not only cause GI upset,” Carbo-Johnson says, “but may also encourage them to fill up on milk and not consume enough complete and balanced food to meet their nutritional needs.”
How Can I Give My Cat Milk Safely?
Our experts recommend foods that contain a touch of milk to satisfy your cat’s cravings without causing digestive upset. This allows your cat to enjoy the creamy flavors while getting complete and balanced nutrition.
By following our experts’ advice, you can keep your cat happy and healthy. Explore our complete list of cat food and cat treats to find the ideal products for your cat.
For more expert advice, tips and answers to all your pressing feline-related questions, visit our Pet Expertise page.