Updated

The asphyxiation death of a dog dropped from the Iditarod Trail Sled Dog Race has outraged animal rights activists who have long criticized the 1,000-mile race as cruel.

People for the Ethical Treatment of Animals is urging Alaska prosecutors to file cruelty charges against those responsible for the death of 5-year-old Dorado, who died last week after being buried by drifting snow at a checkpoint during severe wind.

"It's a horrifying death, and we feel it was totally preventable," PETA cruelty caseworker Kristin Simon said Tuesday.

It was the first Iditarod dog death since 2009, when six dogs died, Iditarod chief veterinarian Stuart Nelson said.

The dog was found dead Friday morning 260 miles (418 kilometers) from the finish line. Dorado and other dropped dogs were last checked about 3 a.m. that day. The death was discovered as much as five hours later, according to race spokeswoman Erin McLarnon.

McLarnon referred further questions to Iditarod race officials, who didn't immediately return phone calls to the Associated Press seeking comment but sent an email response to the AP Tuesday night.

"Iditarod does not engage in any dialogue which involves PETA," the statement said.

Dorado belonged to the team of Iditarod rookie Paige Drobny. The dog was dropped from the race March 11 and was being held in a lot set up to care for dogs left behind because of illness, injury, or tiredness. Dorado was removed from the race March 11 because he was moving stiffly, according to a blog posted on the website for the Squid Acres Kennel run by Drobny and her husband. Iditarod officials have said Dorado was otherwise healthy.

Drobny, 38, continued in the race with the rest of her team, finishing Thursday in 34th place.

Drobny's husband, Cody Strathe, said the couple has asked race organizers to implement new protocols on how dropped dogs are cared for. Strathe said changes sought from the Iditarod Trail Committee include boosting the number of helpers at checkpoints to check on dogs more often, providing adequate shelter and increasing the number of flights to get the dogs out more quickly.

"We thought that our dog was being cared for," he said. "That's the race organization's responsibility. We, as mushers, trusted them."

Race officials have said the weather delayed efforts to transport dropped dogs sooner.

There were at least 135 dogs in the lot that night, and a race official told the Anchorage Daily News that locals, volunteers and veterinarians worked on protecting the animals from blowing snow and wind.

Most of the dogs stayed the night inside two airport buildings, while Dorado was among three dozen dogs held in a spot behind the buildings that handlers reportedly believed would protect them from the wind.

Nome District Attorney John Earthman said no decision has been made on whether to pursue charges.

"I believe I recognize their issue, which I believe is that somebody committed criminal negligence by leaving this dog out in the winter weather in western Alaska," he said. "Whether someone can be successfully prosecuted for that, you know, I couldn't tell you. That remains to be seen."

Every year, the Iditarod is criticized by animal advocates as being an event that can be deadly for dogs and that the animals are forced to run. PETA says at least 142 dogs have died since the Iditarod began in 1973.

Mushers and race supporters say the race celebrates world-class canine athletes that have been conditioned through diet and training to perform at the highest levels of health after decades of research and advancements in animal care.