[OwnedByJezebel]

I used to wonder why dogs don't have belly buttons. After all, they develop in a sack (placenta) and have an umbilical cord when they are born, just like humans. (OMG -- a belly button would be so cute, but it would probably become a hygiene issue with stuff getting in there).

Then I googled it, and found out why. It seems that the mammals with a longer gestation period (humans, elephants, etc) have navels, mammals with shorter gestation periods do not.

On some dogs, you can actually feel a little spot on their belly where the skin is thicker, and that is their navel. I got my previous Yorkie when she was nine months old, with a promise to spay her. There was a little lump, very easily palpated, in the area of where her umbilical cord would have been attached. I thought it might be a hernia. When she was spayed, the vet checked it and said there was no hernia, just a thick piece of tissue. It was her "belly button."