We all love a cute puppy, but what's even cuter than that? Answer: Identical puppy twins!
Researchers at the University of Pretoria in South Africa have confirmed in a research paper that they discovered identical Irish wolfhound twins.
The male puppies are believed to be the first identical, or monozygotic, twins ever confirmed in the dog species.
"To the best of our knowledge, this is the first report of monozygotic twinning in the dog confirmed using DNA profiling," they wrote.
The twins were discovered after the mother dog's owner brought her to veterinarian Kurt de Cramer, the BBC reported.
The dog's owner told him that dog had been in labor with puppies for two hours with no results, the researchers said.
De Cramer performed a C-section on the dog, and delivered a litter of seven puppies. During the labor, de Cramer noticed a bulge that appeared to be one puppy in a placenta.
However, when de Cramer delivered the puppy he found another in the same placenta.
The vet told the BBC he immediately realized he may have found some special puppies. Blood tests later revealed that the puppies were indeed identical.
Although these are the first identical dog twins ever found, researcher Carolynne Joone told the BBC it's possible they are not the first to be born.
She said that it's impossible to know exactly how many identical puppy twins have existed, because some are likely delivered without anyone noticing they share a placenta.
However, she said they are probably "rare," since these are the first to have been confirmed.
"There have been rumors about twins in dogs before," she said. "We just happened to be lucky enough to be able to confirm it genetically."