A sample complaint letter to Neighbor about his Dog.
Dear Sam (Your Neighbor Name)
Though reluctantly, I draw your attention to the nuisance being caused by your dog. Your dog seems to be habitual of barking at every passerby quite fiercely and as such, has become quite a nuisance. Yesterday, when my younger son was passing by your house, your dog fiercely barked at him and tried to jump on him. My younger son has become very afraid of it.
I request you to keep a proper check on your dog and tie it up at a place, distant from your gate, so that even its barking may not cause fear to the people who pass near your gate.