Yukon Quest musher Terry Williams has scratched from the race following the death of one of his dogs, race organizers said this morning.

Williams scratched at 8:21 Wednesday evening at the Carmacks checkpoint following the death.

The dog in question is an eight-year-old named Bags.

Head veterinarian Kathleen McGill and race marshall Hans Oettli spoke to the media earlier this afternoon on the death.

"Unfortunately it's a very traumatic event for all of us,” Oettli said.

McGill, who conducted a preliminary necropsy early this morning after arriving in Carmacks, said this early in the investigation it appears the cause of death is a cardiac disease that may have been a birth defect.

"First off I'd like to send out my condolences to Terry and his family,” McGill said.

The veterinarian said the ailment was a silent cardiac disease, that gave no indication in earlier vet checks.

"All of the vet checks along the way pointed to a healthy dog,” McGill said. "The heart rates were normal.”

Oettli said Williams had so far been doing well on the trail.

"He was doing a very good job,” Oettli said.

McGill said the team dog's lifestyle could have contributed to the longevity of his life with such a condition.

"I think we'll find in this dog that he lived longer as an athlete than he would have as a pet dog,” McGill said.

The results from the necropsy will be sent to a pathologist for further investigation. Williams has requested a full pathology report. Results will be released in approximately two weeks.

McGill said this is her first death in her five years as head veterinarian for the Yukon Quest.

The last deaths of sled dogs in the Quest were in 2007 when three dogs died, in a year that McGill was absent from the race.

Before that, in 2002 a dog died. Neither cause of death could be confirmed as of press time.

Oettli said the death was Williams' reason for scratching.

"It's losing one of your friends,” he said.

As stated in the official rules governing the race, the musher can be disqualified from the race upon the death of a dog, as decided by race officials.

In other Quest news, Jennifer Raffaeli of Fox, Alaska was issued a 30-minute time penalty at the Braeburn checkpoint after she received outside assistance for repairs done to her sled to fix a safety concern.

The time penalty was tacked onto her mandatory eight-hour layover in Braeburn. Raffaeli left the final checkpoint before the Whitehorse finish line at 3:06 a.m.

Two teams finished the race overnight, with Kelley Griffin of Wasilla, Alaska, crossing the finish line at 6:02 p.m. with nine dogs. The veteran was surprised at the number of fans who turned out to greet her.

Also finishing was Cindy Barrand of Kasilof, Alaska, after having a 30-minute time penalty added to her layover in Braeburn for receiving outside assistance.

Barrand pulled into Whitehorse with 13 dogs. She is so far the musher to finish with the largest team, having dropped only one dog over the 1,600-kilometre race.

Expected to finish today is Bart de Marie, a Belgian musher now living in Christopher Lake, Sask.

Whitehorse's Jocelyne LeBlanc is still on the trail, currently carrying the Red Lantern with seven dogs.

The rookie left the Carmacks checkpoint at 2:34 this morning.

All dog teams had reportedly passed through the McCabe Creek hospitality stop.