They are hypoallergenic: they do not contain any element that activates canine allergies. They do not contain cereals, nor gluten. When chewing the antler melts into small grains generating a sandy effect that rubs against tartar and plaque, as if it were a toothbrush. No heat content. Size S (25-50 gr) Size M (51-80 gr) Size L (81-120 gr) Size XL (121-170 gr)