A team of dogs before the start of the 2015 Iditarod. Reuters

The Iditarod Trail Sled Dog Race, a grueling endurance test that stretches approximately 1,000 miles across some of Alaska's roughest terrain, is underway, and the self-proclaimed "Last Great Race on Earth" has sparked renewed debate over animal rights. People for the Ethical Treatment of Animals, especially, has taken up the cause, sending out anti-Iditarod information before the event, which began Saturday in Willow.

"Every Iditarod means a lifetime of suffering for dogs who may be literally run to death," PETA Senior Vice President of Cruelty Investigations Daphna Nachminovitch said in a press release. "PETA is calling for this dangerous, cruel race to be canceled permanently, before one more dog suffers a catastrophic breakdown on the trail."

The Sled Dog Action Coalition reports 144 dogs have died in the history of the Iditarod -- 23 since 2004, according to a PETA press release. In recent years the race has seemingly taken steps to make it safer. No dogs died in four of the past five years, the Alaska Dispatch News reported.

One dog died in 2013 when left at a designated drop-point in what was considered a bad accident. The dog, a 5-year-old named Dorado, was left under veterinary care at the drop-point but was left outside overnight (along with 30 other dogs) and asphyxiated after getting buried under blowing snow, the Dispatch reported. PETA initially called for charges against Paige Drobny, Dorado’s musher, but later apologized amid the threat of a lawsuit against the organization since Drobny had no way of knowing about or stopping the accident, the report said.

PETA has often also commented on the dogs being forced to run the 1,000-mile course that usually takes eight-to-10 days. PETA wrote in a blog post the dogs are allowed little rest, suffer muscle injuries, dehydration, intestinal viruses or bleeding stomach ulcers. The organization also said in a statement dogs who aren’t fast runners are treated like “defective equipment,” and have been killed, abandoned or given to overworked shelters.

Supporters of the race often point to the dogs’ enjoyment while running the race, call the health claims exaggerated, and point to the large teams of veterinarians on hand at the Iditarod. The dogs are certainly bred and trained to be the canine equivalent of ultra-marathoners and are known for their ability to cover long distances. Advancements in veterinary care has helped ease the physical stresses the event puts on the dogs. Dogs that do not pass pre-race EKG screenings, blood tests and other exams are not allowed to run. Also, over-the-counter antacid Prilosec has helped prevent gastric ulcers that often caused serious problems in Iditarod dogs.

It’s certainly a complicated and evolving debate, as different animal rights groups take different stances. PETA is wholly against mushing a team of sled dogs for entertainment in principle. The Mother Nature Network reported in 2012 the Humane Society of the United States released a statement that supported recreational mushing as exercise for huskies, and said the Iditarod had made reformation strides. The HSUS did say it had concerns in its statement, however, and urged the race organizers “to reach for a higher animal care standard.”

The Alaska Society for Prevention of Cruelty to Animals said it does not oppose the Iditarod, but does want better care for all animals and sled dogs, Mother Nature Network reported.