How to train leash reactivity when neighbor’s dog is a menace?

Rescued Waffles, a 2yo pembroke welsh corgi over the summer. He was an absolute angel. 99% of the time never reactive towards other dogs, even when the other dog was barking & lunging, waffles was unbothered. Few months after we got him, we had an incident with our neighbor, Gary, and his dog, idk the breed but it’s a tiny yappy dog that barks at EVERYTHING. Gary was taking his dog out, while we were bringing Waffles in. We have a shared walkway which has a railing on both sides. So we were very close quarters, his dog was going BALLISTIC, and Waffles did as well. Ever since then, Waffles has been reactive towards just about every dog.

I’ve been diligently training against this reactivity with slow success. But this morning on our walk we saw Gary and his dog. Initially waffles had no problem, didn’t react at all. Then Gary’s dog saw us and went off, which lead to Waffles reacting. Gary just stood there letting his dog yap yap yap. I was like “dude?” And he shrugged & said that’s just how the dog is. So he’s got zero intention of trying to do something about it. I ended up being able to get Waffles’ attention and luring him away with treats. Gary’s dog continued barking and Waffles ignored it, even when Gary & his dog FOLLOWED US! Very proud of my boy and he was appropriately rewarded

Just looking for advice on what to do? Gary doesn’t seem to care at all. I don’t really want to weaponize the landlord cause you get one warning about your dog, next complaint means eviction. I don’t want the landlord used against me. But also idk I guess I’m ranting. It’s like a 1 step forward 500 back when we run into Gary’s dog.

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