Once, a very large dog accompanied by a very small dog appeared in my yard, obviously lost. Because of traffic, I let them in. They totally ignored the cats who hid. The big dog immediately reclined on the sofa while the little dog followed me around. Calling the phone number on the big dog's collar, got the owner who soon showed up at the front door. The little dog knew who it was before the owner knocked. After introductions and such, the owner asked where the big dog was. Big boy was on the sofa with no intention of leaving. I had to lead him by his collar to the owner's car.