The domestic cat’s liking of milk is legendary. Therefore it is probably fair to say that cats prefer milk to water. However, it is better to provide your cat with water because it is a natural constituent part of an adult cat’s diet whereas milk is not.
Milk contains fat and cats like fat. I suspect that domestic cats prefer milk over water but domestic cat should not drink cow’s milk as it contains a type of sugar called lactose which the domestic cat cannot metabolize. It can cause diarrhea. Although lactose intolerance varies between domestic cats. I give my cat lactose-free milk sometimes and I give him water most times. He shows no preference for one over the other as far as I can tell.
Domestic cats should be provided with water and they should be encouraged to drink it. Arguably the modern domestic cat does not drink enough water when she is fed a dry cat food diet. Wet cat food contains about 80% water anyway which helps to hydrate a cat. Dry cat food tends to dehydrate cats.
What type of water should we give our cats? Some tap water contains fluoride which may put cats off. Some people swear by running water as provided in water fountain. It appears that the type of container in which the water is placed may affect the degree of attraction the cat has towards the water. It may pay to vary the container to see what happens.
Elisa wrote an article on whether water can make your cat sick. I wrote an article on whether it pays to provide your cat with softened water or not! Cat water is quite a big subject 🙂
And I also wrote a page on how much water a cat should be given daily.