Has he been checked for worms or other physical problems that could cause him not to absorb all the nutrients?
What food are you feeding him? A dog can eat 7-8 cups of a lower quality food while a high quality food will satisfy them with 2-3 cups. It's not just about quantity, it's quality as well
Jasmine - Female Miniature Poodle - born Aug 15, 2010
Loker Delgado Von Stalworth - Male GSD - born Jan 26, 2012
Koda & Zazu - 5 year old male cats
Alex - Male Cocker Spaniel (rescue) - RIP Cuddlebug 2007-2010