Whether you have an innie or an outie, belly buttons are pretty obvious on humans. But have you ever wondered if dogs have belly buttons, too?
Believe it or not, dogs do have belly buttons. They might be covered in fur and almost impossible to find, but they are there. Why do they exist, and what makes them different from human belly buttons?
What Is a Belly Button?
Just like humans, dogs are placental mammals. But what does that mean? There are three types of mammals: marsupials, monotremes, and eutherians (or placental mammals). Marsupials, like kangaroos and wallabies, give birth to their young very early in the development process. Then the embryo continues to grow inside the mother’s pouch. Monotremes include the platypus and echidna. These unusual mammals lay eggs, so their young develop inside the egg rather than inside the mother’s body. Neither of these two classes of mammals develops belly buttons.
Finally, there are the placental mammals, such as humans and dogs. In these species, the embryo develops inside the mother’s womb. And to aid with that development, a new organ called the placenta forms after conception. The purpose of the placenta is to transfer nutrients and oxygen from the blood of the mother to the blood of the young and to transfer waste products from the young to the mother. The baby is attached to the placenta by an umbilical cord, and it’s this cord that gives rise to the belly button, also known as the umbilicus.
During birth, the placenta is delivered, along with the baby, who is still attached by the umbilical cord. However, now it’s up to the baby to begin breathing on their own. The placenta and therefore the umbilical cord no longer serve their original purpose. In humans, the cord is clamped, then cut off, leaving a tiny stub that will fall off in a few weeks. The scar that is left behind when the stub dries up is the belly button.
Why Do Dogs Have Belly Buttons?
When puppies are born, each one is still inside their own fluid-filled sac. The mother dog needs to tear open the sac and lick the puppy clean. She also needs to chew off the umbilical cord, leaving behind a tiny remnant that will dry up and fall away a few days later. If the mother fails to chew the sac or cord, for the puppies’ survival, it’s up to the breeder to take over. Just as in humans, there is a scar left behind when the stump of the umbilical cord falls off. And that scar is your dog’s belly button.
Where Is a Dog’s Belly Button?
So, if dogs have belly buttons just like humans, why are they so hard to see? First, dogs have fur on their abdomens, which can hide signs of the belly button. You might have to part the fur or dig through with your fingers to find it. Second, a dog’s belly button is smaller and flatter than a human’s. It doesn’t pop out or sink in, like on a person. That’s because a puppy’s umbilical cord is much smaller than a human baby’s, so the scar left behind is less dramatic.
To find your dog’s belly button, look in the middle of the abdomen, just beneath the rib cage. You should see a tiny vertical scar or wrinkle on the skin. Alternatively, you might see a whorl of fur over the area. If you can’t see anything, try gently pressing with your fingers and you should feel a firm area where the scar tissue sits. If your dog is sensitive to you touching their stomach, consider handling exercises to teach your pet to feel comfortable with an examination; if they appear to be in pain, contact your veterinarian.
What Is the Purpose of a Dog’s Belly Button?
Sometimes the state of your dog’s belly button can indicate an underlying health issue. A protruding belly button can indicate your puppy’s abdominal muscles didn’t close properly; this can lead to an umbilical hernia, a condition where tissues like fat or organs squeeze through the opening in the abdominal wall. Check with your vet if you notice your dog’s belly button is bulging.
As your dog’s belly button is nothing more than a scar, it serves no functional purpose. Although it is a reminder of your dog’s connection to you as a fellow placental mammal. For the most part, you don’t need to give your dog’s belly button any thought. However, next time you give your dog a belly rub, have a look for their belly button. You might not find it, but it’s definitely there.