Put "background/credit check required" in the ad as a first prescreening tool. 

First Oxford, sent them a DA letter, never responded and I guess they sent it back to Chase.

[Disclosure: I worked at a major medical center for fourteen years as the ADA coordinator and manager of accessibility services, so it's easy for me to see the possibilities.

If they have not confirmed an hour prior to their appointment, I send this text to their phone (which was required as part of their contact information I required in the response to my ad):As I had requested in my email, you have not yet confirmed your apartment showing for this evening, scheduled for 7:00pm.

(ADA, Zoning, Building/ wind codes, fire codes and fire suppression needed etc..).

ADA covers service animals in spaces available to the public like a grocery store or bank.

Down the line we desire to turn the main building (where we now live) into some type of business (ie assisted living) and so we have been developing more bedrooms, choosing ADA flooring and doors, instaling individual heat systems in each bedroom, etc....but the process may take 3-5 years to be able to pay for all the needed improvements. 

However, based on what I've read here, landlords do not have to conform to ADA.  

HUD's requirement is more lenient than the ADA requirement for support animals.

June 2021 driving from Oklahoma City to Ada, OK for a work trip.