According to the shelter that rescued Delilah, "If a dog has no identification then it's not legally their property after three days."
When an animal shelter found a new home for a 6-year-old dog, they had no idea that the animal already had an owner and was tasked with a very important responsibility.
The Florida family needed Delilah the service dog to take care of 8-year-old Zack.
Read: Girl, 11, Sobs Over Losing Her Beloved Pony After 50 Horses Were Poisoned at the Farm
He has autism and social anxiety disorder, and Delilah was specifically trained to detect Zack's seizures.
"She would pace and go crazy and start making noises and circling him, and I knew that Zack was in trouble," his mom, Michele Westenzweig, said to WTSP.
The family housed the service dog since she was a puppy, and Westenzweig said her son and the dog were best of friends.
"They had their own bond," she said.
Days after the family moved from a small town in Alabama to Brandon, Florida in August, Delilah panicked in the new environment and dashed out the open front door.
"It wasn't that she got out because I was neglectful," Westenzweig said.
Read: Driver Arrested in Death of Special Needs Student Allegedly Left On Bus For Entire School Day
The family searched for days and handed out flyers. Every weekend, they went to their local shelter to check if Delilah had been found.
In November, Westenzweig came across the social media page of the Humane Society of Tampa Bay, which was located 45 minutes away. She saw an image of Delilah, who was still wearing the collar the family bought her.
"Oh my gosh! She's there!" she said she yelled in excitement.
But she was heartbroken once again when she called the shelter and discovered her son's best friend had already been adopted by a new family.
According to WTSP, the dog, a Weimaraner, had been adopted within days of being found. Westenzweig had not seen the image of Delilah until months later.
The Humane Society said that when Delilah was found, she had not been wearing her tags, nor did she have a microchip.
Read: Roswell Teen Charged in Theft of Model UFO
"If a dog has no identification then it's not legally their property after three days," a vet at the Humane Society told WTSP.
Officials said they would have put more effort into finding the dog's owners had she been properly identified, but because Delilah was not, the Humane Society wanted to find her a new owner as soon as possible.
However, Westenzweig told InsideEdition.com that Delilah did in fact have her tags on. She said she believes that someone must have had her, and taken the tags off: "I can't think of any other reason why she didn't have them and was so far away."
The Humane Society reached out to Delilah's new family on behalf of the Westenzweig and her son, but the new owners reportedly had no intention of giving her back. Their family had bonded with the dog, they reportedly said.
But, Westenzweig said her son's bond with the dog is stronger, saying he continues to ask for Delilah, months after she had been living with the new family.
"I don't know how to explain it to him and I don't want to tell him she's gone," she said.
Since the family's trauma has started gaining media attention, Westenzweig told InsideEdition.com that Zack has not slept: "My son has been emotional and crying because now he thought she was coming home," she said.
Westenzweig has not been able to afford a new service for Zack because money is tight, she said. Another Weimaraner would cost between $1,000 and $1,500.
Read: Homeless Panhandler Goes Into Cafe, Gets Job Instead of Spare Change
Local attorney Barry Cohen agreed to work with Westenzweig and her family to reach a resolution, WTSP reported.
Watch: Meet Mahe, The Service Dog That Soothed Boy with Autism During Hospital Visit
