The short answer is no, dairy milk is not good for the feline tummy. Cow’s milk has more lactose in it than a mother cat’s milk has, so kittens may experience upset stomach and diarrhea from these elevated levels if dairy milk is consumed. As cats age, most become lactose intolerant, so the likelihood of gastrointestinal upset increases.
Some felines may be able to handle a tablespoon or two of milk without any side effects, but there are no health benefits, so why risk it? If you’re caring for a kitten that’s been separated from its mother, kitten milk replacers are a more appropriate alternative to a mother cat’s milk than dairy milk is (consult with a veterinarian about the correct amount of daily calories). And, if you’re just looking to give your adult cat a special treat, opt for a healthy cat treat instead of milk and you won’t have to worry about the risk of stomach upset.