YABU.
She insists on taking it out for a walk three times a day
Do you expect her to make her dog stay indoors forever, just to suit you?
For her to dump her pet?
What part of walking a dog is so unreasonable & outlandish to you?
through the communal hallway
How else will they get outside - teleport?
and I find it quite intimidating and it is making me sneeze.
Presumably it's on a lead while walking the hallway, so what's to be intimidated by? If you are nervous, politely let your neighbour know her dog scares you, & ask her to make she gives you a wide berth on the occasions you encounter them.
dogs are allowed with permission, and that permission will be revoked for noise nuisance or fouling, which I find weirdly specific.
Of course it's specific. Dogs have permission, unless they are noisy or their owners fail to clean up after them. Rules need to be specific, or how else can the landlord state what rule has been broken?
This dog is a nuisance, just not in the ways listed.
It's not a nuisance. You are allergic, which is unfortunate, but not the dog's, the landlord's or your neighbour's fault.
I'm just so upset, I can't afford to move again, and I am so miserable. I just wished they'd told me.
How long is your walk through the communal hallway, that a dog being taken through it is leaving enough dander to give you symptoms? How frequently do you even encounter the dog in person?
The facemasks are a good idea- I might try that, then at least the owner might get the picture that i am not happy
YABU with knobs on.
If you wish to communicate your unhappiness, talk to your neighbour.
Don't indulge in petty acts of passive aggression instead of clearly stating your discomfort. How do you expect her to infor that your mask-wearing is due to being allergic to her dog if you fail to tell her? - she's not a mind reader.
If you talk to her, she may be able to inform you what times she's planning her walks, so that you can avoid the hallway then. Apart from that, antihistamines as PP suggest. Your neighbour has the right of peaceful enjoyment of her home & her pet, so you need to find a way of coping with it.