I have 2 boston terriers (father and son) both overweight especially the older one. I am cutting out all snacks and measuring out their dry Iams food. Does anyone have any ideas on what else I might could feed them....my boys weigh 43 and 41 pds...the son is deaf, very large frame. Otis the Dad is short, compact and real heavy. I am already walking them everyday except when it is way too hot...any suggestions will be greatly appreciated...