An overhead shot of his body would be helpful to judge. As for fattening him up - add stuff like cottage cheese to his kibble, and there are things call satin balls that are good at adding weight.
http://www.holisticdog.org/Nutrition/Sa ... balls.html
I would just watch the protein level in the Core esp due to his age. Boxers do not stop growing until about 18 months and IMO you should not feed a growing pup anything over 28% protein.
http://www.holisticdog.org/Nutrition/Sa ... balls.html
I would just watch the protein level in the Core esp due to his age. Boxers do not stop growing until about 18 months and IMO you should not feed a growing pup anything over 28% protein.