I'd intended to close the door from the den to the kitchen and then go back out and take the dog home, but by the time I got back outside the dog had vanished. My neighbor had discovered his escape and had gotten him back into her back yard. The whole thing happened so fast that I don't think the dog had time to leave any scent in the den, because when Portia finally went in there she gave no indication of being aware that any stray animal had been in the house. Even without a cat/dog confrontation, I'd say that was the most excitement we've had here all year.
It's too bad Sunni didn't live long enough to meet this dog. She loved playing with dogs, and probably would have been going into his yard to frolic all the time. Portia just isn't nay more fond of the canines family than she is of other cats.