Kristina, This does not sound right since he told you that a pet would be allowed. I can see that he can change the policy and not rent to future tenants but not force current tenants to get rid of their pets. Is there an association for renters in the area where you can ask about this?? Renters do have rights and it sounds like yours are being violated.
So sorry about Remus!
Does anyone here have some facts about the rights of renters????
edit: OK I read responses that were posted while I was writing this!!