"Do dogs and cats have belly buttons?" is a question asked by many a curious animal lover whether young or old. It's a reasonable question given the fact that cats don't have obvious "innies" or "outies" like people do. The short answer is yes, cats have belly buttons.
What's a Belly Button?
The belly button, also called a navel -- or umbilicus, if you want to get truly technical -- is present in all mammals. Cats are mammals, so cats have belly buttons. As with everything anatomical, it had a purpose. The belly button is where the umbilical cord connected mother and unborn baby or, in this case, queen and unborn kitten. As a kitten develops in his mother's womb, he needs sustenance to grow and thrive. Since he can't call out for Meow Mix, he gets that nourishment from his mother's body. The kitten also needs oxygen, likewise delivered through the umbilical cord. The umbilical cord carries these important elements to the kittens and carries waste out of the kittens and back to the mother's body to be disposed of.
When a kitten is born, she is attached to her mother by the umbilical cord. Each kitten in the litter has its own umbilical cord. Once the kitten is fully out of the womb, the placenta is delivered, attached to the kitten via the cord. In the first few moments of a kitten's life outside the mother, she will continue to rely on the oxygen and nutrients coming from the placenta. Eventually, the kitten will give a hearty meow, indicating she is now taking oxygen on her own. The flow of blood in the cord will cease, and the cord is no longer needed.
What Happens Then?
The mother cat licks the cord until it detaches from the placenta, then eats the placenta. This helps keep the nest clean, deters predators who may be lurking and gives the mother extra nutrition. The umbilical cord will be attached to the kitten until such time that it dries up and falls off on its own. Some people want to help their cat by cutting the cord or pulling on the kitten's cord vestige, but it's always best to let nature take its course. Once the cord dries up and falls off the kitten, all that remains of that life-sustaining organ is the belly button.
Belly Button or Spay Scar?
The belly button dramatically decreases in size as the kitty grows, until such time that only the most savvy cat person with 20/20 vision can detect it. This presents a problem for shelter workers. When a stray female cat is brought to the shelter, the shelter staff needs to learn all they can about that cat. They want to know if the cat is healthy, has any communicable diseases and if she's spayed. They may shave the cat's belly to have a better look. They will see a very tiny, almost invisible, whitish scar. But is that a belly button? Or is it a spay incision? Sometimes it's impossible to tell. For this reason, many vets are now adding a drop of blue tattoo ink to the spay incision so anyone checking in the future can see the blue ink and know she is spayed. This obviates the need for expensive ultrasound equipment or unnecessary surgery.
Michelle A. Rivera is the author of many books and articles. She attended the University of Missouri Animal Cruelty School and is certified with the Florida Animal Control Association. She is the executive director of her own nonprofit, Animals 101, Inc. Rivera is an animal-assisted therapist, humane educator, former shelter manager, rescue volunteer coordinator, dog trainer and veterinary technician.