This week my helper and I were mowing a property that I have been maintaining for at least five years. It is an Emerald Zoysia lawn that we mow with John Deere commercial 21 walk behinds. The customer has had one dog for about 15 years which is pretty much deaf and blind. They have another dog that they adopted three years ago which has not given me much trouble. This week they were keeping their sons dog that bears amazing resemblance to a pit bull. My guy was mowing the front yard and I was doing the edging and string trimming. As I trimmed the outside of the fence the new dog came up to the fence and was snarling, growling, and barking at the string trimmer. I decided to try to do the trimming in the back yard and see if the dog was just interested in the string trimmer. I went into the back yard and preceded to back away from the dog while speaking softly to it. However the dog kept approaching me snarling and growling. When it was within a couple of feet from me I tried to kick it, but it jumped up and bit my boot. Then I tried a second time and hit it in the side of the head. We brought the mower into the back yard and started around the yard. After a few minuets the dog went and lay down. When the bag was full and the mower was shut off, the dog came out started to threaten my guy. We found a 1x2 and I used it to herd the dog back into a corner of the yard so that we could switch bags. I did not hit the dog, but apparently I scared it enough that it jumped the fence. When the wife of the customer came home I told her what had happened. She yelled at me and said: THAT DOG HAS NEVER BITTEN ANY-ONE! I said, I really dont care if it hasnt bitten anyone. That dog was threatening us and we took reasonable measures to protect ourselves. She kept saying that the dog had never bitten anyone, and I told her that in the future we would not go into the back yard if any of the dogs were loose. She turned and walked away and said in an angry tone, Well I dont see why your guy had to carry that stick! Later that night the ladys husband, who I normally work with, called me and asked if we had any trouble with the dogs that day. I told him that we had, and I told him how the dog was behaving. He said calmly, Did you hit the dog with that stick. I said, No sir, we carried the stick as a precaution, and let the dog know that if it tried to attack us it was going to get hit. He said, now angrily, THAT DOG HAS NEVER BITTEN ANY-ONE! And if you ever want to mow my yard again you will have to do it by yourself! I do not want your guy mowing my yard ever again! As a matter of fact I dont want him in my yard, NO! I dont want him on my property ever again!! Is that understood!?! I said, Sir, that is an entirely unreasonable request. That guy works with me and he will be there with me if you want me to mow your yard during normal hours. He said, The only way that I will let you keep mowing my yard is if you do it by-your-self, and thats the way it is! So, what would you do or have done?