Can cats drink milk?

The cat's intestines are not built for cow's milk 

Maybe you've given your cat milk at some point, which he probably appreciated. But for the cat to maintain a pleasant stomach, it is best to avoid cow's milk. Cats are lactose intolerant, which means their intestinal systems are not built to tolerate cow's milk. 

Kittens should drink milk 

Kittens should drink milk when they are small, either milk from their mother or kitten milk that you can buy at the pet store. Kittens have an enzyme in their stomach that allows them to break down the lactose and thus tolerate the mother's milk or the kitten's milk. Adult cats, however, lack this enzyme, which can cause the lactose in the milk to start fermenting and they then have an upset stomach.