i bought a vitamin spray when Prue was jsut new and really sick, its flavored with chicken or something, she loves it! I sprayed it in her water bowl ( jsut one squirt) to get her to start drinking water, and it worked like a charm. No i dont even use it in her water, and she drinks with no problems. thats also how i got her and Icis to eat wet food. Wont work with dry food,,dang brats,lol.
Also cat milk is a good source of moisture, and good for them, just not all the time. good luck!