Better to have a guy you can trust than one on a leash!

Let him know in very certain direct terms that he is on a short leash and you will evict if he violates said lease.

It's just so beautiful and sturdy and feels like a floor ought to feel.

You can still require basic things like picking up their waste, keeping them on a leash outside, etc.I highly recommend using a third party verification service to check for the legitimacy of the request to have assistance animals.

We have 3 kids and a well behaved lab mix that goes everywhere with us and runs/walks with us off leash (when allowed/legal). 

I would require that the animal is trained or leashed to pee in one area of the yard and that the pee is immediately wet down to eliminate yellow spots in the lawn. 

Adhere to local ordinances, including leash, vaccination, and tag/licensing, requirements.3.

I just acquired a property with one that is a bit of an eye sore but sturdy.

He said it was sturdy and that he's seen them before.

Get it fixed up so it is safe, functional, and sturdy.