
Its a shame you are having problems with your nabour.
i have barking dogs on both sides. on one side i have a westy that barks a lot, any noise out side she is out and even when there isnt any noises she goes out and barks and barks. she has free acess to the garden all the time by a cat flap and for a while the dog would wake my up most nights. most dogs ive met will bark maby 2 - 5 barks and stop unless there is something making them bark that carries on. but this westy would bark from about 5-20 minits non stop! in the day it wasnt too bad i just turned the tv up but at 1am it was very annoying. i mentioned it to them and i found out that they couldnt hear the dog (apperantly) and they told my to tell the dog to be quiet if i hurd her. i now have her trained to stop if i whistle, and the owners are taking the dog out on more walks now so she doesnt bark like that that often now, so we are both happy and still friends.
on the other side we have newish nabours who have about 6 dogs (dogs seem to magicaly appair over night) the husband says they are hobby breeders but the wife is saying that they dont breed. no one sees them taking the dogs out for walks and they also seem to be outside dogs and dont seem to get much attention. one of the pack will bark, howl, wine and scream often and if we go into our garden it is there barking and barking at us. it is less now that they have settled in but i think 2 people in my road have complained to the council allready. i was putting up new fencing as there dogs had eaten a hold in there fence trying to escape and they hadnt fixed it and the dog was barking the whole time and no one came out to see what was the matter with there dog. but they are slowley getting better.
Dont get me wrong yes i agree dogs bark which i dont mind after all dogs will be dogs, its just when it goes on for like five minits non stop for no reason and happens often then it can becom a nusence, it there is a reason for the barking then fair enough.
If i was you i would speak to your other nabours and see what they think about your dogs barking it may just be a case that she is just targeting you for no reason, in which case im sure the environment agency will figure that out. Maby you could also speak to Cisitancen Advice and see what they suggest.
Prehaps your dogs are barking for a reason, maby there is something living in the garden you dont know about making them bark (pleany of mice up by me).