My two listings have "no pets" in the listing, and in the house rules which "guests must agree to your house rules before they book"
Last week a guest informed me 4.5 hours prior to check in that "Just a quick fyi, I will have my service dog with me" When I replied that I wished she had mentioned this before because we do not permit animals due to allergy, and also in consideration of future guests. The guest then went on to tell me all sorts of things about the dog's food being hypoallergenic, it was clipped, and so on, and that she fell "under Federal ADA protection and non-discrimination laws" I contacted Airbnb and was told that I could deny the visit but I wasn't comfortable doing that, so they stayed. I have had a support case going on with Airbnb, and I read through all the links pertaining to service animals, non- discrimination, cancellation, editing the listing, etc.
The short version is, guests are NOT obligated to tell hosts they are bringing a service animal, even if the listing says no pets (and I know a service animal is not a pet!). Hosts also cannot charge an additional cleaning fee for a service animal.
Hosts can edit their listing to decline pets / animals, but then again, a guest does not have to notify host about a service animal, they just bring them anyway!
I have asked about how a host can legally decline a guest with a service animal. No clear answer.
I have asked what I need to do to get an exemption from having service animals. No clear answer.
I have asked that Airbnb change it's policy to require guests to notify hosts if they are bringing a service animal. Time will tell.
Hosts can only ask these questions:
Do you require the service animal because of a disability?
What work or task has the service animal been trained to perform?