(FILES) Massai, an award-winning chihuahua in the "dog visitor and mediator" category, poses during the hero dog awards ceremony organized by the Centrale Canine at the Paris City Hall on May 24, 2023. Those tiny, fluffy dogs walking down the street may look cute, but beware: they probably have some wolf in themThat is the discovery announced by US scientists on November 24, 2025, who were surprised to find that nearly two thirds of all dog breeds have a detectable amount of wolf DNA. And it is not genetic leftovers from when dogs originally evolved from wolves around 20,000 years ago, but instead suggests that domesticated dogs and wild wolves have interbred within the last few thousand years. (Photo by JOEL SAGET / AFP via Getty Images)