It's an age old question: "is it okay for cats or kittens to drink milk?" Well, yes and no.
Humans are actually the only mammals who can tolerate lactose into adulthood... and not even all of us are equipped to do so. Like all baby mammals, kittens rely on their mother's milk for growth and essential antibodies to protect them from falling ill. Stray orphaned kittens can drink a special formula called KMR (Kitten Milk Replacer) until they are properly weened.
However, an adult cat that drinks milk will most commonly end up with diarrhea.
The worst kind of milk for a cat is cow's milk due to its high lactose percentage. But lactose isn’t the only problem. The casein to whey proportions are all wrong in cow’s milk too.
Instead of spending time trying to find a suitable form of milk for your adult cat, consider the fact that water is *hands down* the best liquid your cat can be drinking... especially for cats condemned to a life of eating only dry cat food. Just by adding some water to your cat's food for every meal, you may be saving them from future urinary infections and even kidney disease.