Feed a variety of foods. Like all animals, cats require fresh, pure water. The amount they drink depends on the kind of food they are fed. Always keep fresh water available. Do not allow your cat to drink from the toilet, flower dish, fish tank, or other unsanitary source.
Some cats favor milk.
However, milk should be considered a food, not a source of water. Offer milk only after the cat has eaten its solid food. A surprising number of cats develop diarrhea and digestive upsets from milk. If you suspect this, avoid feeding milk or other dairy products to your cat. Cats should not be fed dog foods, raw fish or pork, large amounts of liver, raw eggs, or any bones.