Why Don’t Dogs Appear to Have Belly Buttons?
A quick belly button anatomical review
The umbilicus, or “belly button” as it’s more commonly known, once served as the link between the mother and the unborn child. After birth, the umbilicus is either clamped off and cut with a scalpel (humans) or chewed off (thankfully not human moms, but dog moms), essentially severing a connection that is no longer necessary since the newborn is breathing its own air and is capable of nursing. The little nubbin of cord that’s still attached to the skin of the abdomen eventually shrivels up completely and falls off.
Dogs have belly buttons, they’re just flat
The fact is that all mammals that gestate (develop prenatally) inside a placenta have an umbilicus — and that includes dogs. Yours has one too or he’s an alien dog sent by an advanced intergalactic civilization to live among us and observe us. Assuming he’s not terribly Chewbacca-like and that you can get him to cooperate, you should be able to see a little oval-shaped indentation on the abdominal midline, about halfway between the sternum and the genitals.
Dogs’ belly buttons don’t create big lint-trapping depressions like people’s do, and it’s a good thing since it’s likely that they would get pretty gnarly and require routine maintenance. In people, the “floor” of the belly button is referred to as the umbilical tip, and if it protrudes past the opening to the umbilicus, you’ve got yourself an outie.
My dog’s belly button sticks out — is this a problem?
Great question, and I’m glad you asked, because yes, this can be a problem. The abdominal wall (the apparently solid sheet of muscle that protects the important organs in the abdomen) is fused at its center point by a thin line of connective tissue. Sometimes the two halves don’t completely fuse together, and this typically occurs right at the point where the umbilical cord enters the abdomen and allows the exchange of blood and nutrients while the fetus is developing.
The result of this incomplete fusion of the two halves of the abdominal muscle wall is known as an umbilical hernia. The presence of that hole, or hernia, can spell trouble if abdominal contents, such as the small intestines, herniate (protrude) through that hole and become entrapped. This compromises proper movement of the intestines and threatens to block the passage of intestinal contents — a serious and life-threatening emergency that requires surgery to correct.
Thankfully, most umbilical hernias are small and can be easily repaired at the time of spaying or neutering the dog. If your veterinarian discovers an umbilical hernia on your dog or puppy, be sure to watch it closely until it can be surgically addressed — if anything protrudes through the hole, you should be able to easily reduce it (gently push it back into the abdomen) with no problem. If you can’t, your dog may have an intestinal entrapment that needs emergency treatment.