Actually, yes. And in fact, I often do so.
And before the assumptions start to fly, YES all of my dogs are properly trained, YES they are super friendly, NO they do not want to eat children, etc. etc.
I put them away when I feel like it as a common courtesy. For example, friends of ours have a chocolate Lab that is also a wonderful dog and is trained. However, she likes to be near you all the time and has accidentally plopped herself down on my son's legs before and has knocked other children over (again, on accident).
True, if I know you have a dog and it takes precendence over my children & I guess, our friendship, then I will not go to your home.
But on the other hand, there is no way in hell I would have/will have told/tell my grandmothers to stay away all because they are afraid of dogs and just don't care for them in general.
I'm sorry, but close human relationships mean a lot to me and I have no problem kenneling my dogs or chaining them outside when people are over. Now, if I have one out and that person could care less or the kids want to play with the dog, then the dog stays out.
EDIT: Oh, & I can't tell you how many times another set of friends of ours has told us how great their little dogs were and well trained, until Cole tripped & fell & one of the dogs snapped at him (actually tried to make contact). The kicker? Cole didn't even trip on the dog or beside the dog. He was a few steps away.