Alaskan musher Brent Sass arrives at a Yukon Quest checkpoint in Circle City, Alaska, on Sunday. Sass's wheel dog, Taco, was declared dead by race veterinarians on Saturday. A necropsy on the canine found no obvious signs of disease or trauma. (Justin Kennedy/Canadian Press)

A sled dog has died on the Yukon Quest trail over the weekend, according to race officials.

Alaskan musher Brent Sass carried his wheel dog, Taco, in his basket to the Slaven's Roadhouse dog drop on Saturday evening. Veterinarians there declared the dog dead.

A necropsy on Taco revealed "no obvious disease processes or signs of trauma," according to a statement issued Sunday by Allan Hallman, the Yukon Quest's head veterinarian.

"At this time the cause of death is not evident," Hallman said, adding that further tissue examination will be completed in two to four weeks.

A wheel dog is the last dog in a team, meaning it is harnessed closest to the musher's sled. Dogs in the wheel position pull the sled out and around corners or trees.

The Slaven's Roadhouse dog drop is on the Alaskan side of the 1,600-kilometre race through Yukon and Alaska. It is 469 kilometres away from the finish line in Fairbanks, Alaska, according to the Yukon Quest's website.

Continues to race

Sass continues to race and is currently in eighth place. He left the Slaven's Roadhouse dog drop early Sunday morning and passed through the Circle City checkpoint later that day.

"I will be thinking about Taco for a long time," Sass, a veteran musher, told reporters on Sunday.

"But there was never any question that I would not continue to race — Taco would want that."

Meanwhile, Hugh Neff continues to dominate the Yukon Quest. He was the first musher to arrive at the Central checkpoint Sunday at 9:45 p.m. Alaska Time.

"I got into dog mushing to be with dogs, not humans," Neff told reporters.

"I hate to be antisocial or whatever, but I didn't come to do the Quest to go and hang out with a bunch of mushers. I came to run my dogs."

Yukon musher Gatt drops out

Neff departed from the Central checkpoint at 4:11 a.m. Monday, just before Yukon mushers Hans Gatt and Sebastian Schnuelle arrived at the same checkpoint around 4:30 a.m.

But Gatt scratched from the race later on Monday, saying he and his dogs became soaked from some overflow they had encountered on the trail.

With three of his fingers frostbitten, the veteran musher said he is in no shape to care for his dogs properly.

"I could tough it out you know and finish and probably lose a finger or two. It's just I have to take care of the dog team out there; it is not just myself," Gatt told reporters on Monday.

"With three frostbitten fingers, you can't take care of the dog team properly. So it's a bummer, but it's just the way things were going."

This year's Yukon Quest began Feb. 5 from Whitehorse. The first mushers are expected to cross the finish line in Fairbanks sometime this week.

After an easy run through the Yukon side of the race trail, mushers are facing very cold conditions on the Alaska side. It was –38 C in Circle on Sunday night.