that's a tough one to deal with. I own 4.5 acres where my chickens free range. my biggest issue has been neighbors dogs coming in. I have lost a few chickens to them. I have two pit bull/lab/Shepard mixes that I have been training since 8 weeks old who are 3 years old now who guard my flock and take it seriously. If they see a dog chasing the chickens that dog is now marked and they will go after it any time spotted to protect the chickens (they won't kill it just chase it off). Especially after one of the dogs attacked my Italian Greyhound and broke his leg, my two saved him and got the dog away from him. A mix like this can be quite challenging to train I have found out but I have also found out that they are a very intelligent breed and need to be worked to keep from getting bored. that said my neighbors mostly have pit/lab mixes and they don't train them....at all. I have had to take many steps of my own to deal with it because if you ask your neighbors they tend to start complaining because they have to take care of their dogs. I guess the most important question to ask is, do you get along with these neighbors? do you have to go out of your way to keep it civil between you? or can you pretty much ignore them and then are able to take the steps to protect your flock, like calling animal control. I've currently chosen to stay civil with my neighbors because they are actually nice people, but I am also not giving up free ranging so I have just warned that if my dogs take your dog down on my land then it is self defense and I am very sorry but I have a livelihood to protect. Best of luck and I hope that your neighbors will work something out.