Add Yahoo as a preferred source to see more of our stories on Google. If you've ever been to a dog park, you know the way the hierarchy works. Big dogs gravitate toward similar sizes to tussle with, ...

It’s a rare sight to see a young pup doing tricks to get the attention of an older dog. Usually, the pet dogs fight to get their owners’ attention or end up fighting when one dog overshadows the other ...

If you've ever been to a dog park, you know the way the hierarchy works. Big dogs gravitate toward similar sizes to tussle with, and the same all the way down. Yes, there are exceptions--familiar dogs ...