New Research Reveals Most Dog Breeds Contain Wolf DNA: What This Means for Your Pet

Dogs and wolves can produce offspring together, though such interbreeding events are considered uncommon.

Those adorable, small fluffy dogs you see on daily walks may appear innocent, but research reveals they likely possess wolf DNA within their genetic makeup.

This surprising discovery was announced Monday by American researchers, who found that approximately two-thirds of all dog breeds contain detectable amounts of wolf genetic material.

Rather than being remnants from dogs' initial evolution from wolves approximately 20,000 years ago, this genetic evidence suggests that domesticated dogs and wild wolves have interbred within just the past few thousand years.

Logan Kistler, curator at the Smithsonian Museum of Natural History and study co-author, clarified to AFP that this doesn't mean "wolves are coming into your house and mixing it up with your pet dog."

The research indicates this genetic exchange has influenced modern dog breeds' size, olfactory capabilities, and even personality traits.

Though dogs and wolves can reproduce together, such interbreeding is generally considered rare.

"Prior to this study, the leading science seemed to suggest that in order for a dog to be a dog, there can't be very much wolf DNA present, if any," explained Audrey Lin, lead study author from the American Museum of Natural History.

To investigate further, researchers analyzed thousands of canine and wolf genomes from publicly accessible databases.

Their findings revealed that over 64 percent of modern dog breeds contain wolf ancestry, with even tiny chihuahuas carrying approximately 0.2 percent wolf DNA.

"This completely makes sense to anyone who owns a chihuahua," Lin remarked humorously.

Among breeds, Czechoslovakian and Saarloos wolfdogs possessed the highest wolf DNA percentage, reaching up to 40 percent.

For companion dog breeds, the Grand Anglo-Francais Tricolore hound ranked highest with approximately five percent wolf DNA. Sight hounds including Salukis and Afghans also showed significant wolf ancestry.

While dogs with wolf DNA typically exhibited larger size, exceptions existed—Saint Bernards showed no detectable wolf ancestry.

The research additionally revealed that 100 percent of village dogs—which live near human settlements without being owned pets—possess wolf ancestry.

Kistler theorized that village dogs, having more opportunities for interaction with wolves, might serve as conduits for wolf DNA entering the domestic dog gene pool.

He suggested that female wolves separated from their packs due to human activities like habitat destruction might end up breeding with stray dogs.

The researchers also compared their genetic findings with personality descriptions used by kennel clubs for different breeds.

Breeds with minimal or no wolf ancestry were more frequently described as friendly, trainable, and affectionate.

Conversely, dogs with higher wolf DNA percentages were more commonly characterized as suspicious of strangers, independent, dignified, or territorial.

Kistler emphasized that breed descriptions are imperfect and cannot predict any individual dog's behavior.

"Wolves are evolved for specific habitats and specific conditions, and dogs have been carried to every corner of the inhabited world by people," he noted.

Dogs have simply adapted to the environments humans introduced them to, benefiting from "wolf genes that gave them advantages in certain contexts," Kistler explained.

For example, numerous Tibetan breeds, including the small fluffy Lhasa Apso, possess a gene called EPAS1 that evolved for high-altitude adaptation. Interestingly, Tibetan wolves carry this same gene.

The comprehensive study was published in the Proceedings of the National Academy of Sciences.