Size Dog weight Petite 11 lbs. and under Medium 11 - 25 lbs. Large 26 - 50 lbs. Extra Large 51 lbs. + C.E.T. Chews are beefhide treats to which an enzyme has been added that helps stop plaque from forming. PLUS the natural abrasion of rawhide chews help clean your dogs teeth. Available in two sizes (small/medium and large).