They moved their dog in, without paying the pet fee.

(make sure your contract specifies that you get deposits and pro-rated rent when you purchase)Only thing you can consider requesting is that the tenants be put onto a new month to month lease. the benefit to this, is oral leases can only convey rent amount. this lease is created by accepting rent from the tenant every month. every other stipulation defaults to state law. this means tenant can show up tomorrow with 3 pets and you cannot do anything about it (except provide notice of lease termination) whatever you do keep the current tenants on month to month.

It is a 40 year old single male who will be moving and has no pets.

Tenant agrees to keep Property reasonably clean and orderly and that any pets permitted on the Property shall not be allowed to obstruct nor interfere with any showing of the Property for rent or sale.

The deals we are finding are the ones where are able to add value through rehab, management, adding pet rents, garage rental, creative income sources such as vending, internet, short term rentals, etc. 

Like a pet addendum, but spookier.

That pet rent should have been coming to me, no?

So i am 2 for 2 on pets when the least says no pets.  

Also....you absolutely can screen the tenants....you are not "forced" to take anyone.To help mitigate the risk of having potential tenants that are "a little rough around the edges I make sure of the following.No Smokers, Period....not even vapers or cigarsNo Drug Users PeriodNO Previous Evictions from within the last 10 yearsNo felonies No pets, period.I have Section 8 tenants in Cuyahoga County (Cleveland), Alameda County (Oakland, CA) and Contra Costa County (Concord, CA).....and it works.

Check the lease, does it have a pet clause in it?