A California woman has shared a heartbreaking video of the moment a nervous shelter dog she is fostering finally let his guard down for a cuddle.

Walter, a 7-year-old miniature poodle, is being fostered by Sylvia Milu from Riverside County's animal shelter in Jurupa Valley, California.

"I picked Walter up at the Riverside shelter to foster and find him a good home," Milu told Newsweek. "He has a broken kneecap that was not treated and didn't heal. He loves going out on short walks and loves to be carried on longer ones."

Walter hasn't let these physical limitations hold him back, though. Milu describes him as a "sweetheart who loves all dogs, people and children."

"Walter can run up and down stairs, jump into the car and even walk around the block," she said. "He loves all dogs and runs up to say hi to everyone. He loves playing with my 7-pound Chihuahua. He loves to stare at me and hear that he's a good boy."

That's not to say Walter has not been left damaged by what happened to him. Milu said the dog, who is thought to be around 7 years old, has been "abandoned repeatedly" and as a result suffers from "significant separation anxiety."

"He was brought in as a stray. Someone just left him someplace. From his behavior, I can tell this has happened many times," Milu said. "He would bark when I went outside to take out the trash. That's not normal. He has also exhibited behavior of being hit in the past."

Matters are further complicated by the fact Walter hasn't been neutered yet, according to Milu, and "doesn't appear intact." She thinks he may have been "bounced around" over failed attempts at potty training.

Milu has addressed this by having Walter wear a "belly band" diaper and remaining patient while he adjusts to his new surroundings.

A little love can go a long way with a shelter dog. A 2018 study published in the journal Applied Animal Behaviour Science found that just 15 minutes of one-on-one petting was enough to boost the overall well-being of a shelter pet.

Walter needed that kind of love from Milu, but it took a while for him to let his guard down after everything he has been through.

"It took a few weeks for him to feel safe," Milu said. "Since most shelter dogs have a history of abuse and neglect, it's likely his broken kneecap was from being thrown or kicked."

Finally, after 14 days together, he felt safe enough to embrace her. A video shared to Milu's TikTok, @sylvimilu, captured the moment, with Walter melting into his new friend's arms with a palpable sense of relief.

Milu isn't sure what the future holds for Walter. "He has labored breathing, which could be a heart issue. Will be running diagnostic tests next week," she said.

A number of visitors to the shelter have expressed an interest in adopting Walter. Milu just wants to make sure whoever does take him on does so for keeps.

"Because of the belly band, I really think Walter needs a person with one dog or someone that has a small dog for him to play with and preferably a yard," she said. "Someone that works from home. Someone that will treat him like family and not just a pet and that can afford proper care. Someone who will be loyal to him."

After what Walter has gone through, that sounds like the least he deserves.