Bones are rigid living organs that have their own supply of blood vessels and nerves. They are made up of minerals, primarily calcium and phosphorous. They make the frame structure of the body. They also protect the delicate internal organs. The skull protects the brain and eyes. The breastplate and ribs protect the heart and lungs. The other bones provide support and locomotion i.e. legs, tail and neck. The bones in the ear provide sound transmission and help the dog to hear. Bones come in different shapes and sizes:-