While blowing leaves off a fence edge today I encountered a bulldog on the oppisite side of a wooden fence. The fence was obviously old and the 2 dogs had knocked some of the planks loose. One of the slats was wide enough that he was able to get his jaws through. He was head butting the fence so hard that I was afraid he was going to knock the next slat out, and then he would be on my side. I was afraid also if I did not try to persuade him to "retreat" that he would keep on till he got through. I whacked him on the head with the blower tube and it only made him madder. I jabbed at him and he took the blower tube into his mouth and was jerking me around pretty good. After he got most of it in his mouth I opened it up full blast and bulldog snot and slobber went flying everywhere. He made a terrible sound like he was belching in reverse. His head (probably just his mouth) looked like it was gonna explode so I let off and I think he decided that he had had enough. I moved on down the fence and when I shut the blower down to start mulching the leaves I heard him still wheezing through the fence. He has been harrassing me all summer through the fence and most of the time would just stick his nose through and bark. Several times when I was trimming the fence I had to be careful and not hit him with the trimmer. I told the owner that I would not hurt the dog for anything, but if he got through the fence and was out to hurt me, then the dog would not look the same when he went back home, if I happen to have the trimmer in hand. I was shaken though, by his strength and the aggressiveness when he got hold of the blower tube. I had a serious talk with the customer today about the condition of the fence and he assured me he would "dog proof" it before I go back next spring. To clarify, one of the dogs was not aggressive at all, in fact I petted him in the past. But the other is too frisky for his good and mine.