We are all familiar with issues related to service animals (specially trained and certified dogs) and assistance animals (such as emotional support animals of any species or breeds).

This post suggests a compromise response to those issues.

Landlords who prohibit animals do so because they

• fear the damage that might be caused by those animals, 
• know it is highly unlikely they will be able to fully recover compensation from the tenant if there is damage, and
• fear litigation if the animals harm someone. 

Other landlords allow pets, but have strongly worded pet clauses or pet addenda to provide protections. If a tenant has an emotional support animal or service animal, none of the "pet" language applies, though.

You should create an Animal Addendum, or Animal Clause, that applies to all animals, whether they are pets or not.  You can't make it more expensive for the disabled person, such as charging a higher rent, additional deposit, or animal-related non-refundable fee. You can require ALL tenants to exercise responsible animal ownership, protect the property, minimize chance of harm to other people, and maintain acceptable noise levels that do not interfere with neighbors' enjoyment of their own property.

A well-written animal clause will require the tenant to:

• Provide proof of current shots, if applicable
• Provide proof of flea control medication, if applicable
• Disclose the name and contact information of the veterinarian caring for the animal, if applicable (hamsters, for example, probably do not have veterinarians)
• Keep dogs in a crate or on a leash at all times when outside the dwelling
• Use a pooper-scooper, whether on the leased premises or another's property
• Vary locations of dog urination, so as not to burn shrubs or lawn
• Empty cat litter boxes daily into outside receptacles
• Control  excessive barking that disturbs the neighbors
• Allow monthly inspections for pet damage
• Immediately clean any pet discharges and immediately report any damage
• Assist with Twice monthly HVAC filter changes for long-haired animals
• Keep pet food supplies in pest-proof containers

I think that if you approach the problem in this manner, you will be more comfortable complying with Fair Housing laws.