Due to more and more people becoming aware of the naturally low thirst drive of felines, there are far too many "recommendations" to go this route floating around. Not only is dry food far too high in carbohydrates to begin with, it still will not come close to the required moisture as cats are
designed by nature to derive 70-75% water from their food.
www.catinfo.org "Speaking of texture, a common question is "can I just soak the dry food in water?" I hedge more than just a bit at this question. Dry food often has a high bacterial content. Mold is also often found in dry food. There have been many deaths of dogs and cats secondary to eating mold mycotoxins, vomitoxins and aflatoxins that often contaminate the grains found in dry food. If you want to try the trick of wetting down the dry food to alter the texture, please leave it out for only 20 to 30 minutes then discard it. Bacteria and mold thrive in moisture."
http://www.catnutrition.org/faq.html#persuading Please, please don't do that. Please. Dry food, when moistened, is essentially transformed into bacterial soup. The bacteria load is extremely high in dry food. Add water to the mix, and you've just created an ideal environment for fungi and bacteria to multiply. When you moisten dry food, for example, you make it possible to quickly grow fungi in the food resulting in vomitoxin, aflatoxin, and mycotoxin production. Vomitoxin is a toxic substance produced by mold that can (and has) contaminated wheat used in dry pet foods resulting in serious illness and even death."