(INSIDE EDITION) Kelly O'Connell and her brown Labrador Charlie were an inseparable couple, even on her wedding day.
Charlie had been at her side for 14 years, and though he was gravely ill from a brain tumor, he managed to walk down the aisle as she married her human partner, James Garvin.
But the trip back proved too much for the dying dog, so maid of honor Katie Lloyd, who is also Kelly's sister, bent down and scooped up all 80 pounds of Charlie and carried him down the aisle.
A photo of the diminutive bridesmaid lugging Charlie from the altar has gone viral, garnering likes and testimonies from fellow dog lovers about the powerful bond between humans and dogs.
"He was my best friend," O'Connell told InsideEdition.com Monday. "He meant the world to me."
She was working in an animal shelter in Buffalo, N.Y., when someone brought in a chocolate-colored Lab that had been abandoned in a shopping cart amid freezing temperatures in a parking lot.
Kelly was 19 and living with her parents while studying to become a veterinarian. She wasn't looking for a pet, she said. But then she set eyes on Charlie and said to herself, "that's my dog."
"There was just some reason that he was mine," she said, trying to explain how she knew at once that she just had to have Charlie.
They grew up together, she says. He loved running with his owner, and could do 20 miles in his prime.
It was on a run, in April, when Charlie had a seizure and a subsequent trip to the vet showed he had a brain tumor, O'Connell said.
There was nothing to be done, O'Connell said, except to make him comfortable and give him medication for the seizures.
A week before her September wedding, O'Connell despaired she would have to put Charlie down. His seizures had been coming fast and furious, and she didn't want him to suffer.
But he perked up, and his seizures abated and O'Connell and Garvin, her soon-to-be husband, happily walked down the aisle with Charlie.
Garvin's dog, Pan, a golden retriever, was also a part of the procession.
Afterward, as the bridal party began to file out, Charlie was unable to stand up. That's when the maid of honor lifted him in her arms.
"I don't know if it was an adrenaline rush... she just scooped him up," O'Connell said. "She was not going to let anyone get him."
Nine days later, Charlie passed. Though O'Connell and her husband are both vets, they had someone come to their house and put him down.
"I contemplated (doing) it," she said. "Obviously being a vet, I've let many dogs go." But when it came to Charlie, "it was just way too hard. I was a mess.
She still grieves losing him. Pan, her husband's dog, seems to be grieving as well, O'Connell says.
"He's been lying around, kind of depressed," she said. "He knows something is going on. He just kept licking Charlie after we put him down. Licking him and licking him and licking him."