5 Dog Breeds With the Most Wolf DNA (and 4 With the Least)

Your dog might sleep under a weighted blanket and bark at a leaf, but genetically, they’re carrying a surprising amount of wolf. A new study published in PNAS dug through nearly 2,700 dog and wolf genomes from the Late Pleistocene through today, and the main idea is simple enough to unsettle every doodle parent you know. Most modern breeds still have bits of wolf DNA, and a fair amount of it came from interbreeding in the past few thousand years, not from ancient divergence.

Logan Kistler of the Smithsonian National Museum of Natural History summed it up neatly in a statement: “Dogs are our buddies, but apparently wolves have been a big part of shaping them into the companions we know and love today.”

The team found that at least 264 modern breeds carry wolf ancestry from mating that occurred roughly 900 dog generations ago, or about 2,600 years in human time. Audrey Lin, an evolutionary biologist at the American Museum of Natural History, said, “Wolf is there,” noting that modern dog genomes “can tolerate” far more wolf DNA than scientists once assumed.

Your Dog Is More Wolf Than You Think

Most dog breeds fall somewhere between zero and 5 percent wolf. A few climb far higher, up to an eye-opening 40 percent. And just to make it fun, size doesn’t predict anything meaningful. Saint Bernards have none. Chihuahuas have 0.2 percent. Lin joked in The Conversation, “This completely makes sense to anyone who owns a Chihuahua.”

Beyond personality quirks, the researchers found that wolf DNA in village dogs often affects olfactory receptors, possibly helping free-living dogs survive in challenging environments. That tracks, since every tested village dog carried wolf DNA.

Below is a breakdown of which breeds lean toward wolf energy and which lean toward couch-potato domestic bliss.

The 5 Most Wolfish Dog Breeds:

• Czechoslovakian Wolfdog: Intentionally bred with wolves in the 20th century, so no mystery here.

• Saarloos Wolfdog: Another deliberate wolf-dog hybrid with high ancestral percentages.

• Arctic sled dogs: Breeds such as Alaskan huskies show elevated wolf ancestry linked to endurance traits.

• West and Central Asian guardian dogs: Examples include Anatolian shepherds that carry meaningful wolf admixture.

• Certain hunting dogs: Working lineages with long histories near wolf populations show elevated percentages.

The 4 Least Wolfish Breeds:

• Bullmastiff: Big, devoted, and genetically far from wolves.

• Saint Bernard: Zero detectable wolf ancestry despite their size and mountain-rescue résumé.

• Chihuahua: Just 0.2 percent wolf, though no one who has watched a Chihuahua stare down a Great Dane will be shocked.

• Many companion breeds: Breeds described as “friendly” or “easy to train” tended to fall on the low-wolf end.

Dogs may live on couches now, but they still carry a faint wild past in their DNA. Most are “a little bit wolfy,” Lin said. Your dog probably agrees, even if their most primal instinct is interrupting your sleep at 3 a.m. for absolutely nothing.