The Marin Humane Society posted the reunion on Facebook, and the video has been shared more than 26,000 times.
In the video, you can see the mother pup, Cora, cowering in the back corner of the shelter's room. The shelter workers said she was scared when she and another dog were surrendered by their owner.
The shelter examined Cora and realized she had recently had puppies. Workers convinced the owner to let the Humane Society take the puppies, who are too young to be parted from their mother.
Cora appears pressed against the wall, cowering in fear. When she hears the sound of her puppies whining, she comes closer to investigate. Her entire body language changes as she greets her lost puppies, and she can't stop wagging her tail.
The cutest part? Cora keeps running back to the dog carrier to make sure no puppies are missing.
The shelter recently named the puppies after Downton Abbey characters since their mom is named Cora. The puppies are named Carson, Branson, Moseley and Edith.