Is this legal in California

I've been renting at this property for four years now. The original owner never prohibited me from having pets, nor did the owner after him. This property was taken over by a rental company and was sold in mid 2024. We had a property manager who was recently switched, who never mentioned anything about a no-pet policy. The new property manager has moved in next door to me and seems to have a really stupid attitude. She's not the owner she's only a property manager and is replaceable. today I got a notice on my door it wasn't even a legitimate letter in the mail it was a notice that she printed out. It states that it's a 3-day notice where she is saying that I need to get rid of my dog who has been here for 4 years by Monday or else I will be evicted. I just paid my rent a few weeks ago when the month started this is not legal there's no way I would have to leave the apartment when I just paid my rent because she doesn't want me to have dogs here. There are also other neighbours who have pets at this place, and she expects everybody to get rid of their pets by Monday. From what I know, this is not legal.