How a warming climate is part of a shift in sled dog genetics

In an archival video of the 1988 Kuskokwim 300 Sled Dog Race or K300, the start line of the race looks distinctly of its time: spectators wear aviator glasses, turtlenecks, and a lot of teal. But it’s not just the people that look different from today, it’s also the dogs.

Broad-chested sled dogs bark at the start line, black and white fuzzy arctic coats alive with energy. Decades later, the dogs at the 2025 start of the K300 Race Committee’s Season Opener look different. They sport slender builds and thinner fur of brown and black.

The tradition of dog mushing has changed a lot throughout its rich history in Alaska. While some changes come from development in the sport, others have been forced by a changing climate. One part of the story is told in the DNA of the dogs themselves.

It’s a shift Carl Erhart has noticed. His personal history with mushing goes back to his grandmother, a Koyukon Athabaskan Alaska Native from Tanana.

“She was the one who originally had dogs back then for transportation,” remembered Erhart. “Everybody had dogs.”

Erhart, a third-generation musher, lives in Fairbanks with his team of 35 dogs. He and his wife, Jennifer Probert Erhart, train and compete in global competitions. They’ve raised their kids on the sport and Erhart said that he cooks for his dogs daily. To say it’s a huge part of their lives would be an understatement. Dog sled racing is their life, as is true for mushers across Alaska.

But growing up in Tanana, Erhart heard stories about a different time. His dad remembers days when dogs pulled sleds to haul wood and water, protect from predators, and travel between villages. Back then, most families had a small team of three to five Alaskan malamutes, and later Siberian huskies, built for the Alaskan cold with thick fur coats and strong builds.

“But these weren’t race dogs by any means,” Earhart distinguished. “These were your companions, your work dogs, you know. A lot different, a different breed than we have now.”

Today, Erhart’s dog team and the life he leads as an Alaskan musher is a game of telephone away from what it was mere generations ago. A series of, in some cases, literal mutations have re-molded the mushing his dad remembers.

“How dog mushing and racing kind of came about in the villages a long time ago was exactly that. In the springtime, they would have carnivals and festivals where everybody gathered,” Erhart said. “And then it would just be human nature to say, ‘Hey, I bet my team is faster than yours.’ ‘Well, oh no, I bet my team is faster than yours.’”

As snowmachines were introduced and commercial goods became a more reliable supplement to subsistence, the tradition survived primarily as a competitive sport. And that posed a problem for work dogs.

“Those dogs could survive the elements really well, not burn a lot of food to stay warm,” said Erhart. “And they were really strong, but something they lacked was those big Siberian huskies don’t have good stamina, so they can’t go on long, long runs like we do nowadays.”

Suddenly, new traits emerged as favorable in the sled dog gene pool. A dog that was lean and fast and could muster a lot of energy was the kind of dog you needed to win a race. Around the early 1900s, the breeding game began.

The Alaskan husky, with ancestral roots in the native village dogs of Alaska’s interior and coast, began being bred selectively to yield a faster race dog. But Erhart said that at the same time, a shifting set of climate conditions played a role in what traits could make for the most competitive canine athlete.

“And then global warming kind of comes around, right? And we get less favorable snow conditions in the winter, and then we’re a little bit warmer in the spring. So now, when we’re having these races, these old Alaska(n) huskies, we’re having to perform in this hotter climate,” Erhart said.

Genes from dogs in climates around the world entered the mix to match the Arctic’s shifting conditions. The Alaskan huskies have been mixed and matched with Irish setters, greyhounds, German shorthaired pointers, and Saluki hounds.

“And the result of that is you have dogs that can perform well in hot, humid weather,” Erhart said.

On the Yukon-Kuskokwim Delta, musher Myron Angstman was a long-time competitor in the K300 and now chairs the race’s committee.

“The basic dog in Bethel in the 1970s was bigger, thicker. Heavier dogs with way more hair, and those kinds of dogs had existed in the villages for a long time,“ Angstman recalled.

Angstman said that in the K300 race specifically, you can still find some dogs that have lineage from breeds along the Yukon River. Less stocky than the Bethel village dog, he said that they were some of the earliest successful dogs in long distance racing, and had the kind of sleekness usually attributed to sprint dogs.

But Angstman remembers when a wave of sleeker breeds hit races in the ’70s, ’80s, and ’90s. Often, the faster breeds of dogs would come in with teams from Anchorage or Fairbanks. They quickly changed the game.

“And they’d look at the dog and they say, ‘Boy, that’s a fast dog,’” Angstman remembered. “And so rather than breed those, interbreed those with the slow dogs from the villages, they would often just breed the ones from Anchorage and Fairbanks with another Anchorage, Fairbanks dog. So they did a whole team full of faster dogs. And so the changeover was quick and dramatic.”

But breeding for a warmer climate has had a ripple effect. The modern breeds can’t all be kenneled outside like the Alaskan malamute or the Siberian husky can. Some of the fastest dogs need to live in the house, which Erhart said isn’t feasible for someone like him with kids and grandkids. He said that it has caused a shift in the sport and who can do it.

“I’m like, ‘Yeah? At what cost to the Alaska(n) Husky are you the best right now?’” Erhart said. “Your dog literally cannot live outside. So in definition, it’s not an Alaska(n) husky sled dog. It’s a pet dog that’s fast.”

What was meant to keep a tie to the old ways has in some ways caused a divide. The tradition looks different than it once did, but there are also other domino effects at play when it comes to mushing and climate change.

The process of fueling dogs has changed as salmon crises build along the Yukon and Kuskokwim rivers. And shifts in the training of the sport are a new piece of the champion’s puzzle as snow has become more of a question than an Alaska staple. We’ll dive into those developments in stories to come.

This story is part of a series looking at the development of sled dog racing and the impact of climate change on mushing in the lead-up to the 2025 K300 race on Feb. 7. Stay tuned for the next parts of the series on KYUK 640AM and online at KYUK.org.

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