Jack Russell nutrition

by Yvonne
(Los Angeles)

I just got a jack russell. Yogi is 3 months old. He is small which leads me to believe he may have been the runt of the litter but he's darling nonetheless. What I am wondering about is what kind of food to give him. I have him on Wellness puppy. He loves it. But he eats constantly and doesn't seem to gain weight. I know they are high energy dogs but would that preclude from gaining weight? And is wellness a good food for them?