Neighbor's Dog Reacting to Worn Fence

[Jacky Johnson]

Hi, I have a neighbor with a baby and his wife next door whom they have a big dog. The dog is sensitive to noise in my backyard near a worn fence where it separates the property line. The dog frequently reacts to any of my activity near the fence and barks and lunges at the fence where the lower horizontal rail has been bulging outward for a long time. Although the fence is old but it still stands, yet it's annoying to hear the dog barks and lunges at the fence. I'm concerned that the continuing lunging of the dog at the fence may collapse the already worn fence. If I want to warn my neighbor diplomatically about his dog's behaviors, how should I go about this? Thank you.