Landlord allowing one tenant to break a verbal agreement but not other tenants
Is it legal for a landlord to have a verbal agreement with all tenants in a two family house and break the contract for some of the tenants and not others? In the two family house that I live in (where I have no written lease, only a verbal agreement that we will pay the rent on the first of each month), we also had a verbal agreement that no more pets would enter the house except the ones that already lived there. However, this verbal agreement took place when we agreed to put down a security deposit which was over a month before we moved in. Then, about 2 weeks after we moved in, the landlord allowed the upstairs tenant to keep another dog that she had purchased at the pet store. About a month later, my roommate handed me a stray cat when I was returning from work that night and told me to take it in or the neighbor would kill it. So I did and the very next day, I had my sister take it to her vet where I paid for all of its shots and tests to ensure that the cat had a clean bill of health (which the cat did) and also scheduled the soonest available appointment to have the cat neutered. Then, the next day I made the landlord aware of the situation, and she told me that I could not keep the cat. So I gave her my 30 day notice. Also, the same day that she told me I could not keep the cat, the upstairs tenants also brought in another pet- a turtle. Is that legal?