The four-year-old Labradoodle/Husky mix spent 21 months on the road away from the Armstrong family before being reunited on Wednesday.
"It is a true blessing," said Janessa Armstrong of Duke being found. "I am tickled to have him back … we love that dog."
Duke, who never wandered away from home, was discovered missing on Valentine's Day of 2012.
"We believed he was dead," said Armstrong of the dog given to her son, Hunter.
Duke turned up in the Chewalla/Hurley, Tenn. area where he was taken in by H.C. and Bonnie Johnson.
"We found him wandering in the area," said H.C. Johnson. "Bonnie and her mother, Virginia Howell, started feeding him and he just stayed around."
The Johnsons had Buster – as they called him – neutered and given shots as the couple provided a home for the lost dog.
Duke was wearing a identification collar when he went missing. By the time he was found almost an hour away from his home, the collar was gone.
"He was such a large dog even though he was a puppy," said Bonnie of the dog found in late February. "He was very unusual for this neighborhood."
H.C. and Bonnie turned a big doll house into a new home for Duke.
"Although he was big, he was gentle as a teddy bear," said Bonnie. "We were going to take care of him until someone claimed him."
As volunteers with the Corinth-Alcorn Animal Shelter, the Johnsons mentioned Duke to shelter media advisor Phyllis Driver. Driver then put the dog's photo on facebook where Janessa Armstrong's sister saw it.
"When I saw the picture, I thought it looked like Duke," said Armstrong.
One characteristic would seal the deal.
"I called the Johnsons and asked if the dog played fetch?" said the owner. "Then I asked if he picked up rocks?"
When the Johnsons answered yes to the rock inquiry, Armstrong knew it was her dog.
"How Duke ended up in Chewalla is a mystery to me, but the Johnsons are true angels," said Janessa after her daughter, Kristen, and son, Hunter, picked up the canine.
Janessa is keeping a close eye on Duke now that he is home.
"He sleeps with me and my husband, Frankie, as he gets use to home again," said Janessa. "I am a big walker and every time I go, he is going with me."