I'm concerned about my dogs wieght. My dog is 18 weeks and weighs only 15 pounds. Im pretty sure hes a runt his mom stopped feeding him two days before i picked him up and he has an under bite. I took him to the vet and the doc said he is perfectly healthy but is just really small and that I shouldnt worry. The mom and the dad was both around 60-65 pounds, the dad was short though. My wife told me that she read somethere on the net that runts dont usually grow alot there first year. I feed him Innova large breed puupy dry mixed with some wet. Could it be something i feed him?