A little more than two months after threatening letters were sent to dog owners in part of Aurora, a dog in that neighborhood died unexpectedly after ingesting what its owner believes was rat poison.

“She had blue eyes,” said Ryan Fontenot, describing his pit bull-lab mix. “That’s kinda where she got the blue in her name from Roxy Blue.”

Ryan Fontenot is the senior pastor at the Rock Church of Denver. He said Roxy Blue was a birthday gift from the church back in June.

“Beautiful, calm, easy, loveable dog,” Fontenot said, describing the five-month old puppy.

RELATED: Threatening letter sent to Aurora dog owners

On Tuesday night, Fontenot said he let Roxy Blue out in the backyard of his home in Aurora’s Summer Valley Ranch neighborhood.

“Just let her roam around the backyard, noticed that she was eating something, didn’t think too much of it,” Fontenot said.

Fontenot noticed something was terribly wrong when he brought Roxy Blue back inside.

“About an hour later, she began to have seizures,” Fontenot said.

Fontenot rushed Roxy Blue to the vet Tuesday night. Fontenot said the vet questioned whether the dog had ingested oil or marijuana.

“There was no way that our dog could have gotten into anything like that,” Fontenot said.

Fontenot said he brought Roxy Blue home, and searched his backyard where he found a nasty surprise.

“There was a rolled up hamburger meat with green rat poison pellets mixed in it all,” he said.

Meanwhile, Roxy Blue’s condition didn’t get any better.

“She just had continual, continual seizures over and over and she passed away maybe early [Wednesday] morning.”

It wasn’t until talking to neighbors on Wednesday that Fontenot learned of the letter that had circulated in his neighborhood in August.

The letter begins with what dog owners interpreted as a threat: “Over 250,000 dogs are poisoned or shot annually over one thing, inconsiderate dog owners who allowed their dogs to bark uncontrollably.”

The letter referenced rat poisoning, mixing broken glass in ground meat and pouring antifreeze in the yard.

“One of the ways that I believe that our dog was poisoned is listed in that letter,” Fontenot explained. “So, I really believe that it’s connected.”

A spokeswoman for the city of Aurora said Animal Services didn’t have any complaints on file referencing the letter from August. However, she confirmed there was an ongoing investigation into the death of Fontenot’s dog.

If you received one of the threatening letters, and would like to file a complaint, you can reach Aurora Animal Services at 303-326-8290.