ANCHORAGE, Alaska (AP) _ The only five-time champion of the Iditarod was ejected from the sled dog race after one of his dogs died, a decision that drew angry protests Tuesday from fans around the nation.

Rick Swenson was disqualified Monday for violating the ``expired dog rule'' that was introduced this year in response to criticism from animal rights groups.

The rule is designed to protect the more than 1,000 dogs in the mushing marathon; last year, two dogs died during the 1,150-mile Anchorage-to-Nome race.

Race officials made their decision hours after Swenson brought a dead dog into Skwentna, just 149 miles into the race, which began Saturday.

Swenson, who had run in 20 of the previous Iditarods without losing a dog, reacted angrily to his ejection.

``There are other dog races in the world,'' he told KTUU-TV. ``The Iditarod has become a circus. There are a lot of people who don't understand dog mushing _ running the dog race.'

Iditarod Rule No. 18 calls for mushers to be disqualified ``unless the cause of death is an external force beyond the musher's control such as a moose or snowmachine.'' Swenson's elimination did not imply deliberate misconduct.

Swenson told race officials that his team went through about 3 feet of open water running on top of the frozen Yentna River and that the team didn't seem right afterward.

He said he stopped and found a 3-year-old female down, and spent 15 minutes trying to revive her. An examination of the carcass failed to turn up a cause of death but ruled out drowning or a broken neck.

Race marshal Bobby Lee said 59 teams had made it through the same spot. He said it was ironic that Swenson was the first to be ousted, because he ``exemplifies the best in dog mushing.''

A rival still in the race, Charlie Boulding, said Swenson's disqualification proved the rule was unfair: ``He's the best dog-care person I've ever been around, and anybody here will tell you the same thing.''

At Iditarod race headquarters, telephone calls poured in.

``All were in favor of Rick and they don't like the rule,'' night shift supervisor Russ Wilmot said. ``They're not happy and that's being nice. I could use stronger language, but there are a lot of people upset from all over the country.''

Three days before the race, mushers protested an effort to interpret the rule strictly, contending an unlimited number of things beyond their control could kill a dog.

But Wayne Pacelle, a vice president with the Humane Society of the United States, said the rule doesn't go far enough.

The race commemorates a 1925 relay of diphtheria serum to Nome during an epidemic. It is named for an old gold-mining town along the route.