Define "service dog"

[Mark Forest]

I have a strict no pet policy, but lately prospective tenants have been saying "but my dog is a service animal." Is there a legal definition in my state of Michigan of a service dog?  I don't think I can even ask a prospective tenant if they have a disability.  I need some legal guidance. Thank you.

[Tyler Ansell]

We get this all the time. They mostly go to document-mills online and generate fake docs. We've even had ones where actual doctors are running websites signing off on these things. What we require is the tenant to have their doctor fill out OUR form, that way there's no faking it and if they actually have a service animal they won't mind.