Causes of Canine Hernias
Hernias in dogs can be either congenital or acquired. Congenital hernias are those that are present at birth; they may or may not have a hereditary component. Congenital hernias involve the failure of some part of an internal or external body wall to close normally during neonatal development and typically involve defects in the diaphragm or other parts of the abdominal wall. Acquired hernias are those that develop sometime after the dog is born. Acquired hernias typically are caused by some sort of blunt traumatic injury, such as exposure to automobile accidents.
Congenital hernias can have a hereditary component – especially inguinal hernias, which are located in the groin area, because there is a well-described genetic predisposition for some dogs to have a delayed closure of a structure called the inguinal or abdominal ring that predisposes them to developing this type of hernia. Dogs with inguinal hernias typically have a noticeable protrusion or lump in the area around their groin, on the underside of their belly towards their rear end.
Naval (umbilical) hernias can be hereditary or can be caused by the umbilical cord being cut too closely to the abdominal wall shortly after a puppy is born. When they are congenital, umbilical hernias are caused by failure of the umbilical ring to close normally. This causes an abnormal bulging or protrusion of abdominal contents into the “belly button” area. Umbilical hernias of any cause are most commonly identified in puppies by about 2 weeks of age, although they are not particularly common in companion dogs.
Acquired hernias usually occur from trauma, such as by automobile accidents or other traumatic events. Kicks from horses, blunt blows and falls are among the common causes of acquired hernias in domestic dogs.
There is no reliable way to actually prevent hernias from occurring in companion dogs. Most authorities suggest that dogs with congenital hernias – especially inguinal hernias – not be used as part of a responsible breeding program, because these hernias may have a hereditary component. Avoidance of blunt traumatic injuries, such as from cars, horses or other sources, will help to prevent acquired hernias.