You have to allow it if their request is reasonable.For example, installing a wheelchair ramp is a legitimate request but some homes aren't suitable (e.g. a Boston brownstone with steep stairs).

The tenant obtained a wheelchair and months later I saw a wheelchair ramp built on my property entrance way.

But some things to consider when you're scanning properties:  Single story, slab foundation, 3br/2 full bath at the least, wide halls/doorways for wheelchair access.  

My Commercial Sale will still give me over $100,000, plus the HELOC money to use and I can start looking for the next Pool Home to fix up and rent in case I want to live in a wheelchair friendly home where I can get my exercise when I am in town in the backyard Pool.

It's also better if you rent to someone with a wheel chair or assisted walking device. 

IF if is a legitimate ESA (and a large percentage are not), then you cannot deny it, or charge additional deposits or rent for it, any more than you could charge her extra for some other medical prescription such as a wheelchair or medication. 

Previous occupant had been in a wheel chair and had done a lot of damage to Sheetrock.

He pays the rent on time however he is wheelchair bound and has caused significant damage to the walls of the unit.

The buildiing has 2 floors with 2 sets of stairs going up but no elevator or wheelchair access.

Listen I know you're in the hospital and it's a touchy subject but I haven't gotten your last payment and I have bills to pay.Since you're no longer using the apartment and probably will need a wheelchair friendly apartment when you come out of the hospital, would you consider us mutually agreeing to terminate your contract?