Hi, I have a faun boxer 15months old ,he is very active and healthy the only problem is , he has a very narrow chest ,he is of 15 months but look like a 9 months old dog .he got a good body and good type similar to his blood line his top line is very clear. but his chest is very narrow . please suggest what to do for getting him a good wide chest . exercises ?? Food ?? ?? then what type of !