Here's a bump to this thread, first to ask the two folks with the problem if it was ever resolved, then to share one incident that I successfully dealt with, and finally to ask for ideas about an ongoing problem.
Many years ago a neighbor's dog had taken to using my backyard as its bathroom, accessing it through the broken fence. I asked the neighbor very politely on two occasions to fix the fence and keep his dog out of the yard, and nothing was done. One afternoon, after cleaning up an almost full grocery bag of doggie do, I took it next door, placed it on the welcome mat, and knocked. The "lady" of the house answered. I explained that I was returning something that belonged to her, and asked her to fix the fence. The stream of expletives that came out of the woman's mouth would have shamed a sailor, and was punctuated with a cigarette thrown at my face. I explained to her that if I have to clean up after her dog again, I'd file a complaint with the police. Then I left.
An hour later a thunderous set of impacts landed on my front door, and it was the neighbor's husband. After he'd run his foul mouth a few minutes (he had nothing on his wife), I interrupted him long enough to remind him I'd asked him several times to keep his dog out of the back yard, and told him if it happens again he'd be contacted by the police. I ended the conversation by telling him how sorry I felt that he was married to someone like that, and shut the door in his face.
Five minutes later I heard sawing and hammering in the back yard and witnessed the world's shoddiest fence repair job in progress. It was, however, good enough until I moved out of the place a year later.
Now, fast forward almost 35 years. I own 13 acres on a flag lot, and every time I use the easement, the neighbor's border collie chases my side-by-side Kubota or truck, and follows me up the drive, growling, hackles raised, lunging and barking at me all the way. If I'm on a motorcycle, he'll bite at the wheels and my feet. I've contacted animal control on several occasions. They've left phone messages and notes on the neighbor's gate, all to no avail. I have videos of the dog barking and lunging, and of it at my house. The fence idea is out: I've already been threatened with legal action if I put one up to protect my ingress/egress rights in the easement. Yesterday was another round of barking and lunging as I walked up to get the mail. My New Year's resolution is to resolve the issue. Today, lifting an idea from this thread, I'm going to write a letter to animal control, and another to the sheriff's office. I'm not optimistic it'll make any difference. Any other ideas?