Neighbors Aggressive Dog Is Keeping Me In My Apartment

Location: Pennsylvania.

I have a long history with my neighbor not controlling their deaf German Shepherd. The dog doesn't seemed trained or cared for well at all. I have to use a set of exterior stairs to leave my apartment. The dog has already gotten loose before and attacked my friend two years ago-there is a police record of this and multiple witnesses.

Lately the owner likes to leave her on a very long lead on her side porch with just a small railing. The dog has tried to jump over the railing to get to us as my husband and I and our friends walk by (on a sidewalk we must use to enter and leave our home). So far she hasn't but the she has broken free so much we expect it soon. I've heard by zoning laws the sidewalk is technically my neighbors property, so the dog is not actually on my property. But it is a threat to safety by guarding my stairs and the walkway and lunging just barely out of reach.

It is apparently very hard to get dogs taken away in my township according to the police officer I already spoke to about this. Multiple reports about this dog have been made. It is technically on a lead, just a ridiculously long one, so it's not loose. The officer told me that provided the dog attacks I am within my legal rights to defend myself. I understand this and carry pepper spray.

Considering the dog waits for you to come down and I'm stuck on the stairs because I can't leave my home, would I be able to legally use the pepper spray and run past while it's incapacitated? Or would I have to call the police to remove the dog rather than willingly enter a place where it can reach me. I'm confused if this would be interpreted as intentionally putting myself into a situation where I know hurting the dog will occur rather it happening unexpectedly.