DAYTON, Ohio — (ABC News) A dog who held an Ohio shelter's record for the longest stay finally found a forever home after 525 days at the Humane Society. 

Cassie, a mixed breed dog estimated to be about 5 years old, first came to the Humane Society of Greater Dayton in Dayton, Ohio, in August 2017 from a high-kill shelter in Kentucky, Brian Weltge, the president and CEO society told "Good Morning America."

"She’s really a sweet dog, she loves people, her picture does a good job of telling what kind of personality she has," Weltge said. "She is a good girl."

While dogs around Cassie kept coming and going in the shelter as they would get adopted, despite taking dog training classes and appearing as the shelter's "Pet of the Week" on various local media, Weltge said that for some reason they had trouble placing her in a forever home.

"It was unusual for a loving dog, a happy dog to be in for that long," Weltge said.

cassie rescue dog ABC
Humane Society of Greater Dayton via ABC News

"We never had a concern with her as it relates to people, she just loves people," he added. "It was hard to understand why she was here for so long."

Still, Weltge said the shelter -- and Cassie -- never lost hope.

"We’re a limited-intake shelter, we have a 99 percent placement rate, even if it takes five years, there is the right person for every pet that gets into our system and it's a matter of finding that right person," Weltge said.

It was when Cassie made an appearance in a commercial for a car dealership, posing as a super good girl on local television stations, that she got her big break.

Weltge said that a local business, The Jeff Schmidt Auto Group, picked Cassie to be in one of their commercials for a promotion that was also helping to raise money for the local Humane Society.

RELATED: Puppy with birth defect receives wheelchair, ready for his fur-ever home

"They picked Cassie and of course she is just cute and fun in the commercial, and this lady just happened to see it, and at the same time she was looking at the website at the dog," Weltge said. "So she took it as fate, and she came and saw the dog and then she fell in love."

It's been less than a week since Cassie found her forever home, and Weltge said, "I haven't heard anything other than they’re happy and doing great."

Weltge said he hopes Cassie's story inspires people at a time when "there is a lot of negativity and feelings of negativity" inundating the internet.

"To see her so happy when she found her forever home just resonates with people," he said.