I recently evicted a veteran (and my background is 30 years working in a VA Medical Center with veterans and having a father, former father-in-law, current partners father and youngest son who were/are all veterans) who was 100 percent service connected and had income at least 7-8 times my rent.  

I have student loans, medical bills form a bad accident, and some dumb stuff from when I was younger.  

A great start is by reading Brandon Turner's book on Investing With Low or No Money Down.The lady who sold us our first property wanted an income stream and not a lump sum so she could continue to receive her medical benefits.

I believe it is illegal to turn away or deny people with "Service Animals" or "Companion Pets" for medical reasons.  

If you have a local VA Medical Center near where you live contact them regarding whether they participate in the "HUD VASH program".  

5.8 cap is OVERPRICED for medical tenants NNN.

With people living longer, we have to consider medical costs, life insurance, long term care, taxes, etc.  

I have zero real estate experience. 20 years in the medical profession.

My second best advice is to ask the prospective tenant who is giving you problems to provide proof from a medical professional stating his disability as well as proof or documentation that his dog has been appropriately trained to the standards that the ADA requires to be considered a service animal.

Plus, Our contractor was also in a major auto accident (not his fault), attacked by a dog (requiring skin grafts to close it up), had a grandmother in ICU, and had a young daughter who required specialized medical care out of town - all during our rehab project.