Not Rory
We know that our dog Rory is a mutt that's usually taken for a pure-bred Lab but weren't sure what she was mixed with. I met a walker on the trail who said that her friend had a Lab/Border Collie mix that looked just like Rory. I Googled the mixed breed and found some convincing photos. The dog pictured above, also a female named Ruthie, has the same chest and paw markings as Rory, as well as the floppy ears that Amy loves. On another site there's a description of the breed's traits that rang some bells:

Collies are very athletic and have great endurance, but a Lab Collie mix is slightly less energetic as well as being slightly less intense. ... They are medium sized dogs, so should not take over your entire house and as they are medium-haired dogs, they only need a minimal amount of grooming.

A slighty less energetic and intense Rory.