Is Milk Harmful to Kittens?

Cow's milk often causes tummy trouble in kitties.
i Martin Poole/Photodisc/Getty Images

If you've spent your entire life thinking kittens need milk to stay healthy and strong, you're partially wrong. Wee kittens require their mother's milk for all their nutritional purposes -- not milk from a cow. Cow's milk can trigger an upset stomach in kitties -- no, thank you.

Mother's Milk

Up until a kitten is about a month old, all he needs to stay healthy is his mother's breast milk -- nothing from a carton! When a kitten is around 4 weeks old or younger, his mother's milk is totally enough to satisfy all of his dietary needs. If mama cat isn't in the picture for whatever reason, either look into getting the kitty a foster feline mom for nursing -- or perhaps bottle feed the little one via a commercial kitten milk replacer.

Cow's Milk

When you picture milk, the image of a cow probably springs to mind. As much as you may enjoy cow's milk yourself, it simply isn't appropriate or safe for kittens. Do not allow your kitten to consume cow's milk. This will likely lead to stomach upset and diarrhea -- no fun for you and definitely no party for your kitten, either. In some cases, it may even cause throwing up, gas and constipation -- blech. Kittens simply are not able to properly digest cow's milk, so don't take the chance. Not to mention, the milk simply doesn't contain the right levels of protein or fat for nurturing a kitty.

Other Types of Milk

Cow's milk isn't the only possible problem. Avoid feeding your cat other types of animal milks, including goat's milk. If a kitten drinks goat's milk, it can bring upon similar unpleasant effects -- not good.


When it comes to deciding on a healthy beverage option for a kitten after weaning, good old-fashioned H20 is the way to go. Ample hydration is essential for a kitten's growth and development, so make sure your little one always has access to plenty of clean water.

Adult Cats

Not only is cow's milk potentially harmful to kittens, it also is potentially harmful to adult cats. Cats in general are lactose intolerant because their bodies often no longer make lactase, the name of an enzyme that is required for healthy dairy digestion. If a cat cannot properly digest dairy, he likely will experience major discomfort -- think diarrhea and gas, ugh. Even if your cat thinks milk is super yummy, it won't make him feel good afterward, so keep the beverage -- and all dairy products -- far, far away from him.

Always check with your veterinarian before changing your pet’s diet, medication, or physical activity routines. This information is not a substitute for a vet’s opinion.

the nest