A dog who had been waiting in a shelter for a real home is pretty obviously ecstatic that someone finally adopted him.

Rocky, who was adopted last spring from Animal Rescue League Shelter & Wildlife Center (ARLSW) in western Pennsylvania, greets his family with a huge smile every time they walk in the door.

He rolls over onto his back, opening up his belly for potential rubs, putting his paws up and smiling wide.

His rescuer is Kathleen, a volunteer at the shelter who came across Rocky while walking the shelter dogs during her shift.

"On Mother's Day, I went to walk dogs as usual and walked several before ending my day," she shared on Facebook. "However, I still had some time before I had to be at work and found that the last dog that needed a walk was Clancy (now Rocky). I went to his kennel and saw his big smile ... I took him out instantly."

As she was taking the dog for a walk, Kathleen took some pictures for Clancy's adoption page on the shelter's website. She also sent one to her husband, Steve.

And the couple got to talking about Clancy β€” they thought maybe they should spend a little time with him to see if he could be their dog.

But when Kathleen called the shelter later that day, she learned that Clancy was on his way to an adoption event. She called Steve and told him to rush to the event to see if Clancy was still available.

"I said that if he got there and he was already gone, I would be sad but happy that he found a home," Kathleen recollected. But then she got a call from Steve: "We have a puppy," he said.

Kathleen left work immediately and rushed home to greet their new dog, whom they renamed Rocky.

Since welcoming him into their home, the couple has learned that this former shelter dog has so much love to give. He never gets enough petting and snuggling. "He has to have all the attention all the time," Kathleen said. "He will sit next to us and grab our arms and hands and pull them towards him to get more attention."

And while he used to sleep in his crate at night, now Rocky snuggles right between Kathleen and Steve in their bed.

"Rocky is the happiest dog ever. Not only does he look like he is smiling naturally, but when we come home after work, he literally smiles," Kathleen said. "He pushes his lips up and smiles with his teeth β€” it makes him look a little vicious, but his tail is wagging so hard that we know he's just so happy to see us come home."

There are almost 200 animals up for adoption at ARLSW right now. To adopt a furry family member, you can visit ARLSW if you're in the Pittsburgh area, or you can visit Adopt-a-Pet to get started adopting a shelter animal anywhere in the country.