My earlier feline friend, I called her Kitty, survived my care for over 15 years. In my mind, I was doing nothing wrong…she never lacked for food or water, the best veterinary care, etc. I fed her what I thought (at the time) was the best food of all, Science Diet. Like many cats that survive that long on dry cat food, she ultimately developed kidney disease, and before her final termination, was being taken to the vet periodically for overnight water injections to keep her going. It was through this experience that I learned that there is a problem getting cats to drink enough water if they are eating dry food. If they are eating wet food it's easier because they simply get most of the water needed from the food itself. In the wild, cats get most or all of their water that way, and their instinct appears to be not to trust still water.
Now I'm worried about my new feline companion Augie. He actually gets a treat of 1/4 to 1/2 can daily (which he generally eats only about half of), and right now, there doesn't seem to be anything wrong. I'd give him more canned food, but while he likes having me or my lady friend give him some canned food, he seems much more interested in actually eating the dry food (Iams, which my friend feeds all her cats). The wet food he mainly likes to shove around with his tongue (apparently absorbing the moisture…) leaving dehydrated muck. The dry food he will actually polish off.
There doesn't seem to be anything wrong, but I can't really tell since he goes outside for one to six hours every night (up to six hours on weekends, but usually no more than 2 hours on weekdays) he does almost all of his business out there, so he hardly uses the litter box at all. This is not a problem, except that I can't determine whether he is getting enough water or not, since I have no way of seeing how much he is urinating or spraying. And since he usually only goes out once per day, I wondered why he was not using the box anyway. Typically cats urinate 2-4 times per day, but it also appears that cats can hold urine for up to 48 hours, so going 22 hours wouldn't be impossible, even if he is perfectly healthy. He has a perfect and perfectly clean litter box inside (which has has used many times before) but days go by before there is the least little bit in the box to clean out.
Anyway, in the spirit of doing everything I can, even if there isn't any specific knowledge that I must do something now, I'm pushing ahead. Since food is now available at two locations in the house, I have put water bowls in both locations also. And now I've taken the big plunge and gotten my cat a Cat Water Fountain, which I've heard my vet and other people mention as the number one thing to do to help encourage cats to drink more. I got the Drinkwell Ceramic Avalon Fountain. It gets very high ratings generally but some note that it is noisier than others, however as sensitive to noise as I am (very much so) it doesn't bother me because it is in the front bedroom (the Queen's Room) and as I am passing by all I hear is a pleasant water tinkling sound, the kind of sound one might have just for its own sake. I probably wouldn't want this in my own bedroom, or the living room (where the stereo is) either, but in the front bedroom I can just barely hear it, if at all, in any other room anyway.