A group of six Doberman mix puppies has something extra special to celebrate: their amazing survival story.

In July 2013, the puppies and four additional siblings were found abandoned in a dumpster behind a gas station, with their umbilical cords still attached. The puppies were only 2 to 3 hours old, reported Texas TV station KXAN.

A Good Samaritan found the puppies and delivered them to Western Nevada’s Pet Network Humane Society. Sadly, four of the puppies died. But the other six were nursed back to health, and last weekend, they had a belated birthday celebration — held at a time when their rescuers, fosters and adoptive families could all attend.

“It was an amazing accomplishment that we could save any of them, against really high odds,” says Beverly Keil, a volunteer who rehabilitated one of the puppies.

Now 80 to 90 pounds each, Reggie, Dobbs, Bandit, Diva, Maisie and Otter came racing into the shelter to celebrate their birthdays together — with individual birthday cakes made just for them.

The group’s executive director, Becky Goodman, says, "This is why we come to work every day — so that we see these types of happy endings."