As a lifetime owner of large breed dogs & a lover of dogs in general I do not disagree with wasp spray as a defense against a large breed problem dog. A 100lb dog can unleash some serious woopass on a bike rider. It is the dog owners responsibility to control and protect the public from their animals. I currently own two 100lb Dobermans that I love dearly but if they threatened anybody I would not blame them for taking what ever measures they felt necessary to protect themselves. It would break my heart to see them killed or maimed in anyway but I would prefer that over them causing injury a person. My dogs are very genital around me & in our home but dogs are very different out on there own especially with other dogs. People are afraid of loose dogs for a reason and rightfully so. They have maimed & killed people on a pretty regular basis so you take what ever measures necessary to protect yourself. I think wasp spray is a great last resort for a real problem animal. The consequences of your dogs actions can be devastating to everyone involved. You might even be doing the dog & owner a favor by taking such action.

On another note I would not hesitate to spray wasp spray into the eyes of a mugger on the mup either, The stuff is pretty accurate at 20 feet.