My 7 year old german shepherd seems to be having trouble losing weight for some reason. He's gained some weight. I been feeding him the same amount of food and giving him the same amount of exercise but he is still not losing weight. I am trying to keep him slim because of his hip dysplasia. My grandparents live at the house with us and I don't know if its because my grandpa sneaks him a treat or two everyday without me knowing or if his metabolism is slowing because of age, I don't know, it could be anything. Just up until recently, my gsd hasn't had trouble losing weight. I would give him same amount of exercise and same amount of food everyday. He wouldn't gain weight. Now it seems he gained weight and its hard for him to lose it so I don't know what could be the reason? I'm still exercising him regularly and his meal sizes are always the same. My guess is that maybe someone has been feeding him treats? Or do you think it could possibly be a health concern and I should take him to the vet?