Thank you all for your insights!
I contacted Airbnb and we figured it out. I did ask the guest the 2 allowed questions. 1. IS the service animal required due to a disability? and 2. What is the service animal trained to do? In Colorado, we are not allowed to ask for a certificate of any kind.
The guest gladly answered and they are currently staying in the airbnb as I type this! The home owner will not be home for a few months so she was totally fine with it as well!
I would never want to offend anyone who requires a service animal of any kind! I just wanted to make sure I dotted all my I's and crossed all my T's especially since I do have a home owner with allergies. I don't want to put anyone's health at risk or keep anyone from being able to rent the home due to this!