Alumna and CALS Prof Studies Genetics of Famed Sled Dog Balto

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A longtime competitive musher herself, Heather Huson ’97 sampled the canine’s DNA from a taxidermized museum exhibit

This story was condensed from a feature in the Cornell Chronicle.

By David Nutt

Balto, the dashing canine renowned for transporting diphtheria antitoxin to Nome, Alaska, in 1925, is the most famous sled dog in history—immortalized in books, films, and a statue in Manhattan’s Central Park.

Now, a Cornell-led project has added a new chapter to his story, by using ancient DNA extraction and analysis to reconstruct his phenotype and identify his genetic connections to Siberian husky and modern sled dog breeds.

The research reveals Balto’s lineage was genetically healthier and less inbred than modern breeds, with characteristics adapted to the extreme environment of 1920s Alaska.

Balto the sled dog
The original Balto—whose animated alter ego would go on to be voiced by Kevin Bacon in a 1995 hit film.

The team’s paper, “Comparative Genomics of Balto, a Famous Historic Dog, Captures Lost Diversity of 1920s Sled Dogs,” was published in Science in April 2023.

The Cornell team was led by the paper’s co-lead author Heather Huson ’97, associate professor of animal science in CALS, who has a personal connection to dog sledding, having raced competitively for almost 25 years throughout North America. Now she studies how genetics shapes the traits—from physiology and speed to behavior and diet—that produce the ideal working canine, including detection and seeing-eye dogs.

When a veterinarian friend who works with Iditarod sled dogs told Huson that he could connect her with the Cleveland Museum of Natural History, where Balto’s taxidermized hide has been displayed since he died at the age of 14 in 1933, Huson leapt at the opportunity to access the famous dog’s DNA.

Heather Huson leading a sled dog race in Fairbanks, AK
Huson racing in Fairbanks, AK, in 2005.

“The kid in me went, ‘I just want to do something with Balto.’ The scientist in me said, ‘What really was Balto’s influence on modern sled dogs?’” Huson says. “Granted, Balto himself wasn’t bred, but he came from some of the most influential lines in modern sled dogs.”

Whereas purebreds are reared under strict guidelines to cultivate specific physical criteria, such as size, coat, and coloring, modern Alaskan sled dogs are mutts that are bred to improve their performance.

“I was enthralled growing up with sled dogs,” Huson said. “They’re amazing athletes; they’re fast, but they have a lot of endurance. Mentally, they have to be tough. What are the genes that make them an awesome sled dog? Why can they do these amazing things that your average dog can’t do?”

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I was enthralled growing up with sled dogs. They’re amazing athletes.

The researchers found that Balto’s DNA clusters most closely with that of Alaskan sled dogs, with a high genetic diversity and a lower burden of potentially damaging genetic variants. He also had substantial ancestral similarity to Siberian huskies, Alaskan malamutes, Greenland sled dogs, and outbred dogs from Asia.

“Siberians were kind of being created at the same time as the modern Alaskan sled dogs,” Huson says. “This shows Balto is at the crux of that. He is showing that early foundation that’s actually similar between sled dogs and Siberians,” Huson said.

One of the benefits of studying a famous dog from the 20th century is that the researchers could consult pictures of Balto to see how accurately his genetic map anticipated his appearance, validating their process. They were able to see that his genotype predicted a combination of coat features that are unusual for modern sled dog breeds, as well as a smaller stature.

Heather Huson as a child with three sled dogs, a sled, and a blue ribbon
A young Huson with furry teammates.

In terms of his metabolism, the researchers found he had enhanced starch digestion—roughly halfway between that of wolves, which are meat-loving protein digesters, and modern dogs, which are more efficient at digesting starch.

The Balto project was a proof of concept, Huson notes; she hopes to use the same process to explore other historical dogs whose hides have been preserved. One obvious candidate: Togo, the sled dog who was arguably more essential in the Nome serum run but has been long overshadowed by Balto, because Balto led the final leg of the relay.

All photos provided.

Published May 1, 2023


  1. Judy Harvey, Class of 1966

    Good to include Togo.
    I raced sled dogs while living in Alaska in the 1970’s. The ‘Alaskan Sled Dog’ then had only a bit of Siberian Husky, but mostly AK village dog mixed with some Southern hunting dog. It was said that sled dogs were bred for a taut backline or tugline. That, health, and mental toughness were all that mattered. It was amazing that long time mushers could recite a detailed genealogy, back through several generations, of every dog.
    This is interesting research, which might confirm why some dogs are kept and some culled. Perhaps there will evolve a way to identify potential lead dogs in a young litter…

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