Where a colleague in a shared space has a genuine medical, allergic, phobic or comparable reason not to be near a dog, that shared space is kept dog-free. A single genuine objection is enough; the person prevails over the companion dog.
This applies to companion dogs only. It does not override an animal the employer is required to accommodate under applicable law; where a colleague's objection and such an animal cannot both be met in the same space, the conflict is resolved through the legal accommodation process, not by this standard.