I don’t have a dog. In fact, I have never had a dog, although I’ve been friendly with other people’s dogs. So maybe my assumptions are off base. But it seems fairly obvious to me that if you have a large and fairly territorial dog, and if lots of little kids are going to be trick-or-treating at your house, and if you’re going to be opening your front door to give the kids candy, then you should do something with your dog other than leave it loose near the front door. Where the kids can wonder whether the big barking dog is going to get them.
And if a kid and/or parent expressed nervousness at this arrangement, I would consider it inappropriate to more or less tell them (even if politely and with a smile) to take a flying (and candy-less) leap.
(Fortunately, another member of the household restrained the dog. At which point, some standing and staring and other body language on my part induced the distributor of candy to hand some over.)
I need Miss Manners. What is dog owner etiquette for Halloween?