My next door neighbor, who is a realtor, boarded his dogs (at a place about 20 minutes away that had tons of outdoor space for them to run around), then repaired his wood floors and had all of his carpets and drapes steam-cleaned. The dogs stayed in boarding until they moved into their new place. I think it was a couple of months altogether. Not ideal, but they also had to juggle the needs of two small children.

If a prospective buyer were to walk in and be allergic, hopefully those measures would minimize any bad reactions they would have to the house.