The death of Cruz -- a 3-year-old Samoyed who was found dead in mid-February just days after competing in his first and last Westminster Kennel Club Dog Show -- has rocked the dog-show community, with those who cared for the dog claiming foul play.

Both Cruz’s co-owner, Lynette Blue, and handler, Robert Chaffin, said that, because of the suspicious chronology of events, they believe he was the victim of poisoning.

“We have gone through all the steps of where he was, what was done, and he was always on a leash," Blue told ABC's "Good Morning America." "He was never outside. He was always with the handler."

Blue, a 67-year-old Samoyed lover who has raised the breed for years, said the prize-winning competitor showed no symptoms of illness until Feb. 16. It wasn’t until four days after Westminster -- when Cruz was in Colorado, vying for the spotlight in another competition -- that his handler suspected something was terribly wrong.

While competing at the annual Rocky Mountain Cluster Dog Show in Denver, Cruz (whose name is short for GCH Polar Mist Cruz'N T'Party At Zamosky) mysteriously began vomiting blood. Chaffin rushed him to Animal Critical Care and Emergency Services in Lakewood, Colo., but despite the efforts of doctors, the fluffy white Samoyed was dead just hours later.

Veterinarians who studied the details of Cruz’s death said his accelerated decline indicated he may have ingested mouse or rat poison, causing an illness that typically takes five days for symptoms to manifest, according to the New York Times,  If poisoning was indeed the culprit, it would mean that Cruz would have had to ingested it while he was at Westminster.

“Dogs are dogs,” Molly Comiskey, the Colorado veterinarian who examined Cruz, told the newspaper. “It’s not anyone’s fault. They eat stuff; they get into things; they make bad decisions.”

But neither Blue nor Chaffin appear to have accepted Comiskey’s theory that Cruz’s death was a mere accident. “It would have been easy for someone to throw something in his cage,” Chaffin said.

The Times itself has reported there have been poisonous precedents at Westminster: In February 1895, the newspaper said eight dogs in the competition were killed by poison, “evidently to settle some grudge.” And three decades earlier at a dog show in Belleview Gardens, England, a bull terrier was poisoned, also reportedly out of spite for his owner.

While neither Blue nor Chaffin could supply a motive for why anyone might have singled out Cruz, Chaffin suggested that it might have been the handiwork of a fanatical animal-rights group such as People for the Ethical Treatment of Animals.

“Unfortunately, dog shows have been plagued by some of these people for years,” Chaffin said. “I’ve heard horror stories about other people’s dogs having their setups tampered with, being poisoned, but I never thought it would come to me.”

Chaffin also recalled seeing an unfamiliar face at Westminster, who chastised him over the removal of Cruz’s vocal cords, a controversial procedure called debarking, as noted by the Times.

Although PETA’s co-founder and president, Ingrid Newkirk, acknowledged that the group does not condone competitions such as Westminster, she said it was absolutely not involved in Cruz’s death, and that accusations to the contrary made "no sense."

“PETA does not sanction that,” Newkirk told the Times. “It’s so scurrilous; it’s so low to even suggest it.”

Blue said that she was still debating how to move forward in the wake of Cruz’s death.

“We have been devastated and in shock,” she said. “This is one of the most painful experiences of my life.”

In a statement quoted by the Associated Press, the Westminster Kennel Club said it was unaware of any evidence to suggest that Cruz had been poisoned.

"We have never, to our knowledge, had an incident at our show where a dog has become ill or was harmed as a result of being poisoned," the club said. "After conversation with the co-owner of the dog in question, it was established that the dog left Georgia on Monday and flew to New York, he was exhibited at our show on Tuesday, and flew to Denver on Wednesday morning where he subsequently became ill on Saturday. Unfortunately, no autopsy was performed, so there are a lot of unanswered questions."