Do dogs have belly buttons?
I imagine they must do, as all other mammals have, but I've not noticed a belly button on any of my dogs.
Katie Banner, by email
Alison Logan, vet, advises…
The umbilical cord attaches the unborn pup to the placenta to act as a channel for nutrients and oxygen to the pup, waste products away from the pup. At birth, the bitch bites through the umbilical cord and with time the remnant attached to the pup withers and dies, eventually dropping off. There is a scar on the belly which may be apparent if you look very closely, clearly visible when we clip up the belly prior to abdominal surgery, for example.
Humans naturally have a belly button rather than a flat scar, reflecting a difference in anatomy, perhaps to do with being bipedal, walking on two feet rather than four? A puppy may have a belly button if it has an umbilical hernia, where the body wall has not closed off properly as it should.