Here’s a mystery: A golden retriever gives birth to a litter of puppies. It’s not her first birth, and something’s weird about these adorable little pups: Though the entire litter is female, some carry Y-chromosomal DNA in their blood, normally present only in males. The explanation? Male cells from one of the mother’s earlier pregnancies stayed in her womb, eventually being passed on to the younger siblings of the dog they came from originally.
This type of thing happens in humans fairly frequently, and according to research from the University of Missouri’s vet school, dogs can get it, too. This means our canine companions could help scientists figure out how it works.
Read the full, original story here: Your Dog Might Have Some Of Its Older Sibling’s Cells