No pets policy vs emotional support animal laws

[Megan Fitzgerald]

I have a strict no pets policy on my 3BR fully furnished mid term rental because it is nicely furnished and decorated with soft furnishings, linens, etc, has a carpeted, finished basement, and a tiny but fully landscaped backyard. Though I'm am animal lover, dogs and cats just have the capacity to do too much damage in a short time to this type of rental. I'd have to double the security deposit, raise the rent by 20%, and double the cleaning fee to even make it worth considering-- which I would if people were willing to pay but the market doesn't support those prices.

HOWEVER I currently have a single man who filled out his application and negotiated 10% lower rent with me. He mentioned his girlfriend would be staying with him occasionally before submitting the application, but she would not be in the lease. After submitting the application and credit check, he also informed me that his girlfriend would be bringing her "emotional support dog" with her during her stays?

Is there a way to say a hard no to that without running afoul of disability laws? Since she is not on the lease, I'm hopeful I can do so. 

How do you all handle emotional support animals? I was surprised that i couldn't even charge people who bring these sorts of pets an additional deep cleaning fee to remove allergens for future guests thinking they had access to a pet fee home.