You want to confirm the person you are talking to is actually a landlord and not one of the tenants friends.Ask if they gave sufficient notice when they vacated, if they had to be reminded of lease rules, if they had extended guests or dog sat for friends etc..

For example, when our maintenance guys recently discovered dog urine on a tenant's carpet, we issued a $25 lease violation and required them to clean it up.That said I don't know the laws in Virginia and your lease may or may not allow for such measures.

LOLnow I get it on vacant ghetto dogs. who cares If close or not.. but when you start to doing this and fibbing to homeowners who are counting on you may want to check your moral compass ... :))) OH God what has the internet done unleashed this attitude..

Personally I'd just charge hefty late fees to discourage this behavior.

Did their behavior change?

Your basically bird dogging for yourself.  

You will not change the facts or the behavior with negotiation.At this point, you hire an attorney.He will have an inspection done by someone who he can later qualify as an expert witness.He will send legal notification to the seller of what the problem is, what the solution is, and the type and amount of damages he will ask the Court to award.He might even take the case on contingency, or partial contingency.But you need to get this under control right now.Good luck.Michael Lantrip

The best guide to future behavior is past behavior.

I read or listen to a podcast every morning while drinking a strong cup of coffee with my dog sound asleep on my lap.  

You also need to come to the table with something of value in return, something like helping them evaluate deals, being their bird dog, etc.