The first dog to die during the 2018 Iditarod had the same underlying cause of death as one during this year's Yukon Quest, officials with The Last Great Race announced Saturday.

A necropsy on Blondie, a 5-year-old male with veteran musher Katherine Keith (bib #51), found that its cause of death was "consistent with aspiration pneumonia," according to an Iditarod statement.

Blondie died at about 12:15 a.m. Thursday at the Koyuk checkpoint, where Keith had dropped the dog Wednesday and it was being treated by a veterinarian for signs of pneumonia. Race standings show Keith reached Nome to take 26th place, finishing the race at 8:35 p.m. Friday with eight dogs.

In February, another 5-year-old male dog, Boppy, died on the Yukon Quest trail in Hugh Neff's team. Neff scratched from the Quest, and a race veterinarian said Boppy had died of aspiration -- choking on its own vomit.

"It's heartbreaking. Absolutely heartbreaking," said KTVA Iditarod analyst and now-retired musher, DeeDee Jonrowe. "And any dog that you've worked with for its lifetime, you've trained, you've spent 24/7 with and there's not a dog on your team that isn't the case with... I know that's true with Katherine's. Those dogs are your best friends. You spend more time with them than any one person in your life. I can guarantee you in the last six months Katherine's spent more time with that dog team than she has with anybody but perhaps her daughter. This is really heartbreaking news. That's all I can say. I know how it feels. You're pondering it and it's heartbreaking. And it wasn't for lack of caring that this happened."

People for the Ethical Treatment of Animals Executive Vice President Tracy Reiman released the following statement in response to Blondie's death:

"Blonde was one of 330 dogs pulled out of the Iditarod during the race so far, likely because of exhaustion, illness, or injury, and his death from a lung problem pinpoints precisely why this race must end. PETA is calling for the release of the veterinary records of every dog removed from this year's race so that a true picture of the enormous suffering that these animals endure can emerge. Mushers are using and abusing dogs and then leaving broken ones behind in their pursuit of the almighty purse."

A group of activists with PETA held a funeral for five dogs that died during last year's Iditarod. One of them died of suspected overheating in a plane, while being transported from a checkpoint -- an incident that prompted Iditarod officials to change race policies.

"These dogs are being treated like machines and they are literally being run to death, "said Tricia LebKuecher, a PETA campaigner who staged the protest. "Eighty-one percent of the dogs who do manage to finish the race suffer lung damage. Their feet become bruised and bloodied, cut by ice. Many suffer stress fractures. They pull muscles, they develop pneumonia; many become sick with intestinal parasites or bleeding stomach ulcers."

People for the Ethical Treatment of Animals staged a funeral on Saturday, March 3, 2018 for five dogs that died during the 2017 Iditarod. (Liz Raines/KTVA)

The dog funeral was the first of its kind staged by PETA at Iditarod.

Copyright 2018 KTVA. All rights reserved.