The visceral skeleton is extremely variable in animals. It consists of bones that are developed in the soft tissues of the body. Among the domestic animals only a few species possess a visceral skeleton. The bones generally conceded to belong to the visceral skeleton are the os cordis and os penis. The os rostri of the pig is open to question as it is apparently derived from the nasal septum (Bone, 1979). Os cordis located around the origin of the aorta and pulmonary artery at the base of the heart in all members of the bovine family. Os penis is located within the penis in all members of dog family (canidae), members of the mink family (mustellidae) and some rodent species (rodentia) as seal, walruses and raccoons (Miller, 1962 and Bone, 1979).
The aim of the present work is to study the os penis from the surgical point of view concerning its shape, length, width, relation to penile urethra and its radiographic appearance in mature dogs.