Inherited a tenant with fleas

[Jenna Stonecipher]

I bought a 4plex last month that has only 1 apartment rented. While doing work in one of the vacant units, it came to our attention that there is a flea infestation. With only one tenant, the source is pretty obvious. This has to be abated before new tenants begin to rent.

What is the best way to handle this? I've called a pest guy and scheduled for him to come out. Should I speak to the tenant about this in person or in writing, both? I want to make sure this is properly documents since eviction may be in our future.

Also, if he's not abating the problem on the animal, then pest treatment will do no good. How can I ensure that he abates the problem?

The lease that he signed with the previous owner allows him to have pets, but they are awful. Is there any way that I can get the pets out without going full eviction?