good input hampus!
in my old office i used to bring them in 1-2 days per month. we designated a dog-free room for visiting clients and allergic employees, and these people didn’t have any reactions.
in this case it should maybe be the other way around, designating one room as a potential dog-zone. preferably a room that is easy to clean.
reasonable dogs are, in my experience, a welcome addition to the office environment, and as long as their humans are reasonable too this works really well. unreasonable people bringing unreasonable things to work will always be a problem.
i believe the reason some places have a no-dog policy is that it’s hard to draw a line for which dogs are ok and which ones are not. one cute yorkshire terrier is of course not an issue for most people - but a herd of wild wolves may be, and the wolf owner may be hard to handle.