Deer and elk shed their antlers once a year. A new rack typically takes 3-4 months to grow. Antlers are primarily made up of calcium: Studies show that shed antlers consist of two main minerals, calcium followed by phosphorus. Dogs are purpose-built to chew and consume bones. A dog's natural chewing process will grind the antlers and crush them into pieces that are able to be swallowed. The high acidity level in a dog's stomach will break these pieces down further allowing the body to absorb calcium and other minerals. Antlers contain no allergens. Free of plastic polymers, starches and chemicals. Antlers are primarily calcium, therefore, there is no protein spike to cause loose stool. Antlers are external bone and are extremely dense. Antlers share similar qualities to raw bone and grind down slowly. Antler is designed by nature to aid in removing tarter build up. Removing tarter prevents tooth decay, bad breath and periodontal diseases. Prolonged chewing release endorphins. Endorphins are known to create feelings of euphoria and enhance the immune system. Stain and Odor Free!