Hydration: A Key Component of Feline Health. Anyone who lives with cats knows all too well that they’re not only some of the fussiest eaters, but they also tend to drink very little. What many people don’t know, however, is that cats should ideally drink about 50 ml of fluid per 1 kg of body mass each day. And this can be tricky, because cats like fresh or flowing water; the stagnant stuff in a bowl doesn’t quite do it for them. Brit Care Soups for cats are an excellent way to boost hydration.