Real milk, not a milk drink, that your cat can enjoy without digestive upset. Cats and kittens love milk, but most cats cannot have regular milk because it is hard to digest. CatSip is real Grade A milk from the dairy that has been specially developed to reduce the risk of digestive problems, which some cats experience with ordinary milk. It is treated with an enzyme, lactase, to break down the milk sugar so your pet doesn't have to.