By the time an old dog named Holden showed up at a local animal shelter in Georgia, he was almost totally defeated — and he had every reason to be.

But in a matter of days, the little dog would be standing up on his hind legs, eager to give kisses.

Holden’s miraculous story of survival started when he showed up at the shelter, clearly neglected and starving. Even though he was shaky and nervous, whenever he saw any bowl of food at the shelter, even cat food, he tried to scarf it down. Holden weighed 25 pounds, about 15 pounds under what he should normally weigh.

The poor pup had just been seized by the police — there had been a drug raid at the house he used to call home. That’s how he ended up in the shelter — but the shelter was already so overcrowded it had no room for him. Holden was in limbo, wrapped up in a blanket in the intake area, waiting while shelter staff reached out urgently via social media for help.

As if all of that weren’t enough to scare a poor little dog, on top of everything else, people were about to discover that Holden had something inside his body that could have slowly killed him.

At the veterinarian, X-rays revealed a 7-pound tumor lodged in Holden’s body, making it hard for him to even eat anything.

Quite amazingly, though, despite all he’d been through, Holden’s tail still responded with an enthusiastic little wag to even the slightest gestures of kindness.

One video shows Holden just after waking up from surgery to remove the tumor. And even though his head is down and he’s clearly disoriented, the sound of a kind voice gets his tail immediately going.

That innate positivity would help Holden make huge strides in the coming days. The first big step was leaving the overcrowded shelter for good, which was happily arranged by Releash Atlanta.

A volunteer named Ashley picked Holden up, and when he looked sad and defeated riding in the back of her car, she gave him hugs and took some selfies with him to cheer him up.

The second step was getting his tumor removed and then recovering at his happy foster home. Thankfully, Melissa Lentz, a seasoned foster mom for scared little dogs, became Holden’s saving grace and her family welcomed him with open arms.

Holden got to meet Lentz’s daughter as well as the nine little dogs currently living at the Lentz home. And Holden has already made great progress — he’s shown his appetite for life is fully intact, as well as his appetite for food.

“I feed him ALL the time,” Lentz told The Dodo, adding that he’s the sweetest guy. But Holden’s journey isn’t over. The tumor had to be biopsied to see if it was cancerous. And Holden will still be looking for a forever home, once he’s ready, despite his old age and health issues.

As she does with many of her foster dogs, Lentz keeps her friends, family and fellow dog lovers updated on Facebook. An update from last week showed a video of Holden learning to shake hands. “He may be old and he may or may not have cancer (biopsy not back yet),” Lentz wrote, “but someone is going to be VERY lucky to have this dog.”

This week, some good news came back from the vet office: The preliminary tests on Holden’s tumor show that it’s probably benign.

Holden still needs some fixing up — he’ll need to go to the dentist and to get neutered — but the pup whose wagging tail showed just how positive he could be in even the roughest of times is finally getting a taste of the good life. And it’s putting a spring in his step that he’ll probably have for the rest of his life. It only took a little kindness.