FARMINGTON — It's one of the hardest decisions you can make: knowing when it's time to put your pet to sleep.

For the Coates family, it was very sad when their dog, Zoey, got sick. The family decided to take her to the vet to be euthanized.

Six months later, the Coates received a big surprise when they found out their dog was still alive.

Last fall, Zoey, a boxer breed, started having seizures. The dog also had a large mass on her side. The family thought it was cancerous and that it was slowly taking her life.

Tawny Coates, Zoey's owner, said her family had been through a very hard time over the past year. Her husband robbed a bank, the family lost their home after he went to prison, and then the family dog got ill.

"This felt like a final stab." Tawny Coates said. "Like it was just one too many things. I knew it was going to be what pushed my kids to their breaking point."

"I slept with Zoey almost every night," said Coates' 11-year-old son Jaxton. "She was my best friend."

On Nov. 29, 2016, Coates asked her father to do what she could not: take Zoey to Bayview Animal Hospital in Farmington to be euthanized.

Six months later, she thought her family was ready for a new dog just like Zoey.

"I knew we wanted a boxer," Tawny Coates said. "I knew a boxer would help my son heal."

She started looking online and came across a rescue page for boxers. It was there, in the photos, that she saw an image she will never forget.

"I see the Boxer Town rescue page and I'm like, 'That looks like my dog.' Then I thought, 'I'm crazy,' but I click on it anyway and zoom in and say, 'No, that's my dog!'" Coates said.

But it couldn't be, could it? Zoey had been euthanized and Coates had the paperwork to prove it: a receipt for $215 for euthanasia and cremation, Zoey's medical record, which lists euthanasia, and even a sympathy card from the staff at the clinic.

To figure out how this happened, KSL Investigators sat down with Dr. Mary Smart. She's the vet Zoey was brought in to see.

"From my interaction with Mr. Coates, it seemed pretty obvious to me that they didn't want the dog," Smart said.

Here's where it gets tricky. Smart said she told Coates' father, Larry, that Zoey did not need to be euthanized.

"In my professional opinion, this was a dog that had years to live and I didn't want to put the dog down," Smart said. "I was trying to save its life."

Smart said she discussed other options that could save Zoey. Surgery, medication, or even "do nothing," but let the dog live.

"Did he seem open to any of your suggestions?" asked KSL TV's Mike Headrick.

"No, no," Smart said. "He kept repeating that he wanted to put the dog down."

Larry Coates told a different story and called Smart's explanation a "complete falsehood." He said he did take Zoey in to be euthanized, but claims he was never given any other options that would have saved the dog's life.

Smart contacted a rescue group who was willing to take Zoey. She then took the money for the euthanasia and put it toward a surgery to remove the lump on the dog's back. A picture of Zoey in Smart's exam room showed up on the rescue group's Facebook page the same day the Coates family thought she was put to sleep.

"Why didn't you call the family?" asked Headrick.

"I screwed up," Smart said. "I should have called the family. Had I any inkling that they might at all be interested in having the dog back, I would have for sure called. But after my conversation with Mr. Coates, it just seemed very obvious to me that they didn't want the dog."

"It breaks my heart because I don't understand why somebody would do this to my family," Tawny Coates said.

The big question for some might be: Did the vet do the right thing? In Smart's words, she was trying to save an animal's life. For the answer, we went to Dr. Drew Allen, a member of Utah's Veterinary Board.

"A pet is legally classified as someone's property," said Allen. "As veterinarians, we're obligated to follow what we agree to do with that quote, property."

Allen said this is a legal and ethical issue. He said vets are often asked to euthanize an animal even if they don't want to. So, they have a couple choices —decline and send the pet owner to another vet or come up with another solution. But once the pet owner pays for a service, the vet is obligated to do it.

"As much as we are in this profession for the love of the animals, we need to make sure we're not putting just what we think is best for the animal above the owners and the humans involved in the equation as well," Allen said.

In the end, the Coates family did get their dog back. Now, they're making up for lost time — time that they ironically have thanks to Smart's choice.

"If I had followed procedure, if I had followed protocol, if I had done what Mr. Coates asked me, they wouldn't have their dog," Smart said. "Their dog would have been euthanized and this family would be without their dog."

The Veterinary Board might look at disciplinary action in Dr. Smart's case, but no official complaint has been filed against her.