I've considered this myself. Especially if others may be in the line of fire. I'd offer up my weak side forearm and then shoot once it has latched. Depending on the breed of dog this may not be advisable.There is a school of thought to let the dog latch onto you and then bust it. May or may not be the thing to always do but if it does get a hold of you it is a much easier target.
I am not one to invite a dog bite and the possible disease that may go with it but just something that has been discussed.