Cats need to drink about 240ml of water daily as adult cats weighing about 4kg, using a formula of 60ml/kg of weight.
This can also be obtained through their food – dry diets have about 8-10% moisture, canned food about 70-80%. An ideal diet for your cat should contain both dry and wet food, as well as free access to drinking water at all times. The more wet food you feed your cat, the more moisture he will obtain through his food:
After we got our water fountain, which has a maximum capacity of 3l, I find that it lasts us about 5 days before I have to refill it again. This means that our cats are drinking about 200ml a day on average. Our cats have a diet of both wet and dry food, so this amount is still okay for them.
Remember also that if your cat is sick, he need to drink more water to replace any water loss through fever, flu or diarrhoea. To make sure he gets enough, rehydrate him frequently with water mixed with glucose and salt, add a bit more salt to his food to make him drink more water, or provide food with higher moisture content for him while he recovers.
Water is important for cats; lack of which has immediate effects on their health. Dehydration symptoms include teary eyes, with discharge from their eyes and nose. Long term ill-effects of a lack of water include urinary tract infection and kidney problems.