I have a couple of houseguests this weekend. ("Weekend" seems to mean Wednesday through Monday. I wish that was standard in my life, too.) They seem to be getting along well enough (they come from different homes and hadn't met before), and they're delightful dogs. So I decided to take this opportunity to do some serious dog research. Don't worry, I am IACUC certified!
And I decided to post the results of my research here, for your edification: