A new viral video is proving to be another example friendships that transcend barriers – quite literally in this case.

Posted by Erin Richter of Savage, Minnesota, USA, it shows a little boy playing catch with a dog who is on the other side of a fence between two houses.

According to Richter, her son Landon, now three, discovered over a year ago that if he threw a ball over their neighbour’s fence, Dozer, the Labrador retriever next door, would give it back.

Chad Nelson, Landon’s father, posted the video on twitter and it has since then been watched nearly 12 million times.

“My son plays with him every time they are both outside,” Richter told CBS News. She added that Dozer’s owner knows her dog often plays with Landon. “She says she knows when we are playing with him because he comes inside out of breath.”