I believe the behavior will continue to decline.  

His behavior is not shmarmy or unethical at all.

Tenants are supposed to be on their "best behavior" during the application process, putting themselves in the most positive light possible.  

If they were a good employee (renter) you would expect them to stop the behavior in question (pet using your property as a toilet) and you would warn them that any damage would come out of their paycheck (security deposit). 

They still may try to deny it, but if I've got dates and times and specific examples, they know that I'm already starting to document a case against them.I have successfully remedied this situation for me with a simple conversation with the tenant, warning them that if the behavior continues it would escalate into written documentation of a violation of their lease, which can potentially lead to eviction.

If they need to change from one service animal to another, then we fill out a new Service Animal Agreement.We also include name and contact information regarding the service animal's veterinarian and emergency care taker.Here is an excerpt from our Service Animal Agreement regarding other terms:"Tenant agrees to:1.Provide proper care for the animal in accordance with veterinary recommendations or ASPCA (American Society for the Prevention of Cruelty to Animals) guidelines.See www.aspca.org.2.Not to leave the animal unattended for any unreasonable periods of time.3.Adhere to local ordinances, including leash, vaccination, and tag/licensing, requirements.4.Clean up after the animal and dispose of animal waste properly and quickly.5.Not to leave animal food or water outside the dwelling, as it could attract other animals.6.Keep the animal from being noisy, aggressive, or from causing any annoyance or discomfort to others.7.Immediately remedy any complaints that arise from animal behavior.8.Immediately pay for any damage, loss, or expense caused to others by the animal.9.Provide animal with regular health care, to include vaccinations as recommended by a veterinarian.10.Arrange for an emergency caretaker for the animal.Tenant agrees to indemnify, hold harmless and defend Landlord against all liability, judgments, expenses (including attorney fees), or claims by third parties for any injury to any person or damage to property caused by Tenant’s animal.Landlord reserves the right to revoke permission to keep the animal should Tenant break this agreement or provide false or misleading information."

That is the kind of behavior I am out to stop! 

They need a place to live and I "personally" have not seen this translate to bad tenant behavior.

Is this behavior really worth the possibility of losing your freedom or your house, car, and bank accounts?

I can't count the times in the past 10 years that I've gotten a late payment excuse from someone wearing obviously brand new designer clothes, sporting a brand new smart phone or otherwise displaying some kind of behavior that was incongruous to their situation (new car, new tv, new bbq pit, daughter runs in and says she can't wait until they leave this weekend to go to six flags, "lost my job" but they're leaving the house freshly showered wearing their uniform....)At the end of the day, you have to do what you can live with, but if you're asking for advice, my guess is you're looking for support for what you already know you have to do.