You've no doubt seen instances of identical human twins, but have you ever heard of identical twin puppies? While it's certainly true that some dogs appear so similar they could be twins, there had never been a confirmed case of pups that shared identical DNA – until now.
Researchers at the South African University of Pretoria recently confirmed the world’s first identical twin puppies, a set of Irish Wolfhounds delivered by veterinarian Kurt de Cramer. A paper published about the puppies explains: "To the best of our knowledge, this is the first report of monozygotic twinning in the dog confirmed using DNA profiling."
The twins were born by caesarean section from a litter of nine and were discovered sharing a second placenta following the births of their seven siblings. Instantly, the vet's interest was piqued, and he performed blood tests in order to determine whether they could be identical twins.
"When I realized that the puppies were of the same gender and that they had very similar markings, I also immediately suspected that they might be identical twins having originated from the splitting of an embryo," de Cramer told the BBC. DNA tests at six weeks of age confirmed the vet's suspicions.
While this discovery is no doubt ground-breaking, it is perfectly possible that cases of identical twins in dogs have existed before. Carolynne Joone, a researcher with James Cook University in Australia, spoke to the BBC and explained: "There have been rumors about twins in dogs before. We just happened to be lucky enough to be able to confirm it genetically." She went on to say that identical pups could have been born without sharing a placenta – a phenomenon unlikely to raise a vet's suspicions.
The Irish Wolfhounds in question, named Cullen and Romulus, do have minute differences in the markings on their paws, chests, and tails, which will certainly make it easier to tell the two apart!
Photo ©Kurt de Cramer