Finally tonight, rooting for some true underdogs. An elderly mutt and her owners are on a mission to find homes for older dogs in shelters. Saying they make the best pets. So, see what you think.... See More
Finally tonight, rooting for some true underdogs. An elderly mutt and her owners are on a mission to find homes for older dogs in shelters. Saying they make the best pets. So, see what you think. Here's ABC's Dan Harris, with a couple and their friend, who are "America strong." Reporter: This is the face that launched a campaign to save some of America's most vulnerable dogs. She looks like a punk rocker. But she acts like a nun. Reporter: Her name is Susie. Her owners, Brandon Stanton and his girlfriend, Erin o'sullivan. Brandon is the guy behind the wildly popular blog and book, "Humans of New York," which features pictures of interesting new yorkers. He met Susie on the job. What about this dog that's -- This -- I had never seen a dog that was that interesting. Reporter: He adopted her despite her age, she's 13. She loves him so much. Reporter: Susie is lucky. Most people prefer puppies. Older dogs have a hard time finding a home. The alternative is to either be in a shelter or even worse. Reporter: Despite the fact that senior dogs actually have a lot going for them. They're easier. If you're just looking for someone to completely love you, the senior pet is the way to go. Reporter: So, Erin here decided to take up Susie's cause, starting a Facebook page, called Susie's senior dogs to find aging dogs like heartthrob here a new family. She is cute. Brandon posted it on his blog and boom, it went viral. The first dog adopted in just two days, 13-year-old Nina. Give me double-paw. Yeah. Reporter: Soon, taco adopted in Georgia. Max in Virginia Beach and rosco in Oregon. All-told more than 20 dogs finding forever homes thus far. One funny little face and one big, viral movement saving lives tonight, in that classic "America strong" tradition by rooting for the underdog. Dan Harris, ABC news, New York.
This transcript has been automatically generated and may not be 100% accurate.