Anatomy of the Canine Male Urogenital System (An Overview) . Notes and importance: The os penis is attached to the distal (cranial) portion.
Male canids have a bulbus glandis at the base of their penises. The penis sometimes emerges . Miller's Anatomy of the Dog. Elsevier Health Sciences. ISBN 978-0-323-26623-9. Gary England (18 October 2012). Dog Breeding, Whelping and Puppy Care.
The baculum is a bone found in the penis of many placental mammals. It is absent in the human penis, but present in the penises of other primates, such as the gorilla and chimpanzee. The bone is located above the male urethra, and it aids sexual reproduction Baculum of a dog's penis; the arrow shows the urethral sulcus.