In the world of dog-sled racing, it is known as "culling" - weeding out the dogs too big, too aggressive or too old to make the team.
The dog owners call it a humane process. But detractors say that's not always the case.In September, two-time Iditarod racer Frank Winkler was charged with 14 counts of animal cruelty after a crate full of dead and dying puppies was found in the back of his pickup truck. Prosecutors say Winkler hit the puppies over the head with the blunt end of an ax. His trial is set for Dec. 11.
Winkler has said in court documents that he shot some of the dogs - a kinder method, according to veterinarians - and that he was just following advice from fellow racers, known as mushers.
Mushers deny such actions are common and contend the uneducated in their ranks are ruining the sport's good name. But executives at the Humane Society of the United States say such cases confirm their worst fears.
"We believe that the culling and killing of surplus sled dogs and animals that are bred for racing is much broader and much more widespread" than the industry admits, said society Vice President David Wills in Washington, D.C. "It's the ugly side of the industry."
The 1,163-mile Iditarod, known as the Last Great Race on Earth, usually lasts from 11 days to two weeks. About a third of the 1,500 dogs that start the race are flown out because they become sick, injured or exhausted. At least one or two dogs die in each Iditarod, most from pneumonia, intestinal obstructions and "sudden death syndrome" - dropping in harness for unknown reasons.
Veterinarians say mushers should let professionals put unsuitable animals to sleep. But vets can be expensive, and in Alaska, getting to one isn't always possible.
"Everybody agrees that an ax handle is not the way to do it," said Sherri Hayden, who owns a wilderness lodge in remote central Alaska with her husband, Jack, and offers recreational mushing. "But we know that (breeding) accidents do happen, and you need to take care of them."