Re: Feline/canine bellybuttons

Dear Justin,

Thanks for your question! As you learned from Lynn Bry, dogs and cats do have belly buttons. This is a physical remnant of life in the womb because it physically marks the spot where the umbilical cord connected the animal to its mother. In the case of animals which carry more than one fetus at a time, each fetus must have an umbilical cord in order to survive. However, these multiple umbilical cords do not usually get tangled. The main reason is that each embryo is contained in the mother’s uterus as a single unit. There are a series of membranes that surround the developing embryo and the umbilical cord, thus isolating them from neighboring structures.

Just in case you’re interested in more detail… The amniotic membrane surrounds the developing embryo and umbilical cord, and also contains a fluid, known as the amniotic fluid, that cushions the embryo. The amniotic membrane is then enclosed in another membrane called the chorion.

I hope this information is helpful! Please do not hesitate to contact me with any further questions.

Nikki
nmdavis@fas.harvard.edu