Do Male Dogs Have Nipples?
Male dogs do have nipples, typically about 8 to 10 depending on whether they are a small or large breed. They are found in a dog's torso starting from the chest down to the abdomen near the groin area and have corresponding names based on their position. If a dog has 10 nipples, for example, he'd have two cranial thoracic, two caudal thoracic, two cranial abdominal, two caudal abdominal, and two inguinal nipples.
Aside from dogs, almost all male mammals have nipples. Whereas a female's nipples serve the important function of secreting milk to feed their young, a male's nipples do not have a biological purpose. They are simply there because their formation precedes the process called sex differentiation during the embryonic stage of development. From an evolutionary perspective, they remain despite having no use because having them or not neither provides advantage nor poses any harm to the species.