There is a n airbnb box you can tick i think that says "pets live on property".
Removing pet dander is difficult - we run portable hepa filters in the house. Hepa is good for guests who come down with respiratory infections btw.
You MUST mention your cat usually resides on property for lots of reasons not just guest allergy.
We are also worried the guest may allow our ragdoll Meowfoy to escape outside if they are not careful with checking where he is before opening the doors or windows ! Or bring a pet who will hurt him.
My pets are not always in residence on day one so i can concentrate on settling the guest in - except the fish who are indoors in aquaria clearly shown in the photos
Some guests apparently also particularly look forward to meeting Meowfoy. (Fluffy not so much) bwhahaha airbnb needs another button for "pet attraction" I'm thinking about listing interacting with them as an optional event so we don't dissapoint.