"Service Animals" Or are they really pets?

[Robert Shoffner]

I have run into a tenant that had decided to take a very legalistic approach with me following a request for access to the property.  A few days later I followed with a proper notice of intent to inspect the property.  My notice mentioned restraining any pets, so no one gets hurt.  He contacted me about this and asked what time he needed to make sure his "service animals" were restrained.  Now he is not blind, physically crippled, or in any other way in true 'need' of service animals, however that is his claim.

My questions, in terms of protecting myself as a landlord are 'what documents must he provide to prove these are truly service animals?'  

Also, I inherited this tenant from the previous owner.  They conveyed the lease to me but there was neither a pet addendum, nor any reference to service animals (or anything to otherwise document he has any).  'Wouldn't there need to be a pet addendum and/or something in writing referencing service animals from the previous owner?'  If not what should I do?