Your dog or your girlfriend/boyfriend?
A couple I know had a problem. The guy and his dog moved in. The dog bit the woman's kid. The woman said the dog had to go. The dog went and the guy went with him.
The scene just reminded me of the Harlan Ellison story, "A Boy and His Dog".
The reason for having to decide doesn't matter. Just the choice: If forced to decide between your dog or the significant other you just moved in with, which would you give up?
(I'm going to be interested how the sexes break out on this.)