Neff keeps Quest lead; Sass team dog dies CAUSE UNKNOWN: Necropsy reveals nothing obvious.

With Yukon Quest leader Hugh Neff and a three-man chase long gone from Circle City on Sunday, Brent Sass of Fairbanks remained at the checkpoint, mourning the loss of Taco, a wheel dog that died Saturday.

Two days earlier, Sass became the hero of the race, rescuing Hans Gatt -- the leader of the pack that is pursuing Neff -- from wind-hammered American Summit. Sass hooked Gatt's team to his sled and, powered by his lead dog Silver, pulled both teams over the 3,420-foot summit. From there the teams mushed into Eagle.

After resting at Eagle, Sass and his team took off for Slaven's Roadhouse, 101 miles away. They stopped for six hours at Trout Creek, where Taco ate and rested well, Sass told reporters Sunday, according to a report on the race website.

Shortly after the team returned to the trail, Taco collapsed, the report said. "By the time Brent set his hook and ran to the dog, he was gone," the report said.

Sass acquired Taco when he was a puppy, the report said. "I will be thinking about him for years," Sass said.

Sass, a race veteran with a history of coming to the aid of mushers in trouble, was the eighth to arrive in Circle City. Nineteen racers remain in the 1,000-mile race from Whitehorse to Fairbanks.

Neff, a Tok musher seeking his first Quest title after placing third last year and second the year before, arrived at Circle at 10:20 p.m. Saturday. He left at 6:42 a.m. Sunday with 13 dogs.

Gatt, the defending champion, arrived at 8:02 a.m. He dropped one dog and left with a nine-dog team at 12:35 p.m. -- more than six hours behind Neff.

The race appears to be for second place, and it is truly a race. Rookie Dallas Seavey and 2009 champions Sebastian Schnuelle all left Circle with 64 minutes of each other, with Seavey and Schnuelle running neck and neck.

Late Sunday night, Allen Hallman, the Quest's head veterinarian, announced the results of the necropsy of Taco

"The necropsy revealed no obvious disease processes or signs of trauma," he said in a report at yukonquest.com. "At this time the cause of death is not evident."

A histopathological examination of tissue will be available in two to four weeks, he said.