Why do puppy mill rescues need another dog in their home?

Puppy mill rescues have lived their entire lives in a small wire cage and been used for commercial breeding.  They have lived with 300 or more other dogs nearby, but have not been socialized with humans.  They have not lived in a house nor heard household noises.  It is all new and strange to them.

Having another dog in their new home gives them a level of comfort and they model the other dog’s behavior.  They will watch and see the other dog going up to people, and notice that the other dog is calm and unstressed if the dishwasher starts or another noise occurs.  It gives them a level of trust having another dog around. 

We tried in the past to place some dogs alone. An example was Jake, who didn’t pay any attention to the foster family’s dogs and only wanted to be with people. The potential adopters, a couple who knew the fosters, came to visit Jake many times, and he loved them! Whenever they walked in the door he ran to them, jumping up and wanting to be held.  We finally made the exception and let them adopt him even though they did not have another dog.

A couple of days after adoption, they called to let us know they thought Jake was sick. He sat and shook and would not go near anyone. They wondered if they should visit the vet. We had an idea as to what was wrong – we asked one of our fosters who lived nearby to pay a visit with one of her dogs. 

The moment she walked in the door with her dog, Jake (while not seeming to pay any attention to her dog) turned and ran to his adopters with tail wagging happily. 

A few years ago, our board decided that it was simply too hard on our rescues to try to adjust to their new life without a buddy, so we made it a formal requirement.