ok i grew up thinking that dry cat food was better than moist but i hear that u think differently. what is the best food for cats i have a 4 year old 2 year old and about 5 month old?(dont know for sure). if its canned what kind and also how do i do it so they dont get dirreha. any input would be appritiated. currently they all get dry iams adult formula. also 2 old the cats have already gotten bladderinfection but not stones or crystals.