Male and female anatomical homologies in the perineum of the dog (Canis familiaris).

Understanding the homologies between male and female perineal structure helps both evolutionary biologists and clinicians better understand the evolution and anatomy of canines. Domestic dogs (Canis familiaris) play an important role in human society, and canine perineal anatomy is important for maintaining dogs' reproductive health for successful breeding and a wide variety of pathologies. Here, we investigate homologies between male and female perineal structure, identifying structures based on common function, anatomical relationships and attachments. In this investigation we dissected 21 male and female large-breed dogs. We find broad structural homologies between male and female dogs related to erection, micturition and defecation, including muscles, fasciae and erectile tissue. Using these homologies will help anatomists and clinicians interpret the anatomical organization of the perineum, a notoriously difficult area of anatomy.