India, Nov. 20 -- Dusseldorf (dpa) - Cats may gobble their food in seconds, but the water bowl often goes untouched. And that can be a problem: staying properly hydrated is crucial for feline health. Dry cat food contains very little water - around 7% to 10% - meaning cats need to drink extra to stay hydrated, explains the German Pet Supplies Industry Association. How much water does a cat need? A cat's daily water intake depends on its weight and level of activity. The general guideline is 50 to 60 millilitres per kilogram of body weight. For example, a 4-kilogram cat needs about 200 to 240 millilitres of water per day, which is roughly equivalent to the volume of a small glass of juice. Without enough fluid, cats can develop kidney proble...