In 2012, a viral video showed baboons in Saudi Arabia capturing a puppy and cohabitating with wild dogs. The issue was hotly debated, and the video raised questions about the symbiotic relationship between baboons and dogs. Still, there was no conclusive evidence that the baboons kept dogs as pets, per se.
In the YouTube video, baboons grab, play and mingle with the dogs. They are shown sleeping in the same area and grooming one another. The narrator goes so far as to say that the dogs stand guard at night, as a dog would for a human.
However, beyond the video there isn't any scientific evidence that baboon-dog interaction is comparable to human-dog relationships. There are certain clues within the video that support this: the baboons do not feed the dogs, and one of the dogs has a collar indicating that it's already domesticated.
They likely interact because of their shared environment. The video was shot in a trash dump where both the dogs and baboons have frequent contact with each other as well as with humans.
Still, some experts are intrigued that the two species coexist and even cohabitate. They are both "socially plastic," which means that they are geared to be more interactive, even with other species. Some scientists believe that there is more to study, if given the right opportunity.