Although some television shows, cartoons, and even comics and storybooks often portray cats to love all things milk, not all cats should have milk. In fact, milk may be hard for some cats like the British Shorthair to digest. Although young cats or kittens are able to digest milk, it is believed that as they age they lose the enzyme that enables digestion. The main reason for indigestible milk is the lactose within it. Because grown cats cannot digest lactose, it starts to ferment in their stomachs causing diarrhea or in worse cases vomiting. Symptoms of lactose intolerance usually occur within 8 to 12 hours. If your British Shorthair cat has diarrhea or is vomiting, please call your veterinarian right away. Some cats, however, can tolerate milk or even other dairy products such as yogurt and cheese. Your animal hospital London, ON may recommend keeping all milk products out of your cat’s diet.