What do you do when you are aware that a neighbor's rental property (not yours) has a potential mold issue because everyone that rents it moves out after getting horribly sick with pneumonia and recurring respiratory infections?

Will their ESA dog cause a health problem for other people (allergic reactions and respiratory issues etc.)The above are legitimate reasons to deny an ESA dog from your home.

It is unlikely mold would grow that quickly, most molds are not hazardous to health, and even the dangerous molds are typically only dangerous to people with existing respiratory problems.

Reach out to some of the hospital staffing departments to get a feel for how likely travel medical professionals (not just nurses - think Physical, Occupational and Respiratory Therapists, Phlebotomists, Pharmacists and others) are to come to your area and ask if they provide housing referrals for their traveling staff.

I have been in the medical field for 4 years as a respiratory therapist.

@Shawn WestbrookA voltage detector is one to think about 😉 and all appropriate PPE (personal protective equipment) Safety glasses, gloves and respiratory protection.

See https://www.epa.gov/moldBut since the tenants already informed you that they are asthmatic and considering that mold can cause irritation to the respiratory system, I would move them out immediately to be on the safer side.

Sorry I was MIA, been laid up with a really bad respiratory thing(tested negative for everything, just a bad cold).

It’s a respiratory virus that the elderly or those with underlying immune system issues are most vulnerable as they already are with other viruses.  

Graduated from college a year ago as a Respiratory Therapist at the age of 20.