Emotional support animals are a somewhat fraught place in fair housing law. If the potential tenant has medical recommendation that states the tenant requires the support animals, there are many landlords who will say “I don’t believe that’s a valid recommendation.” If you, acting as the agent or the landlord, countermand objective recommendations by the medical person, there is a risk you get dinged for acting outside the scope of your real estate license. Basically, if you follow your client’s direction and say “Tenant, I don’t trust your therapist and that’s why I turned down your request for accommodation,” there’s potentially a lawsuit awaiting you and the first question is “what grounds do you have for distrusting the therapist’s opinion and why are you qualified to have that opinion?”
https://www.animallaw.info/article/summary-emotional-support-animal-cases has some solid explanations of emotional support animal cases happening around the nation. The more you read through these cases, the more it becomes clear that ESAs are sort of a wild west of fair housing laws. Emotional Support animals are not covered as service animals [service animals are either dogs or miniature horses and they are legally considered something closer to an extension of their person], but an emotional support animal is able to be requested as “reasonable accommodation” under the Americans with Disabilities Act. Reasonable Accommodation requests are modifications to existing rules and policies that are required to allow a person with a disability to make equal enjoyment of the space. Hence, if the apartment has a rule that says “no dogs,” an emotional support animal request is a request to provide a unique exemption to the rule for the accommodation requestor. Nonetheless, Reasonable Accommodations must be reasonable. Typically, there is some level of nexus that is required [see section IX of the website link], so it is not unreasonable in many situations to ask the person to go back to the doctor and have the doctor explain why the pets alleviate this specific illness. You have the ability to work with the tenant regarding the reasonability of the request; limiting the geography [dog may only be off leash on the fenced north lawn], mandating maintenance [scoop it up afterwards], etc. If you are negotiating reasonable limitations to the accommodation though, your limitations need to be reasonable ones. The number of pets would normally be within the range of negotiation for the reasonable accommodation, but something like telling the person “I only permit hypoallergenic dogs that match the paint scheme” would be outside the range of reasonability.
Be aware, as you negotiate with the potential tenant over support animals, each question you ask or each limitation you propose on the scope of the accommodation request is a delay in the property owner’s response to the reasonable accommodation request. This generally raises the temperature and increases the likelihood that someone sues the property owner for discrimination because the landlord is pocket veto-ing the accommodation request. Things like demanding that the certification come from a local healthcare provider is not necessarily advised, as it could be treated as just throwing roadblocks in the way of the tenant on a basis of their disability, and broad statements like “I don’t trust internet therapists” will not win the day in court as a landlord’s reason for denying a reasonable accommodation request.