So, for an eight month old pup weighing in at 31 lbs, and a seven month old pup weighing in at 37 lbs, how much should I be feeding? Should it still be the 2-3% of their weight? Also, does neutering and spaying have much of a difference? I've heard that when you neuter a dog, you should feed less to keep him from getting fat. Forgot the reason, but it was some scientificy-type reason...or maybe not. haha.