Apartments and dogs? 😥

What if I don’t disclose that I have a small dog when I sign a lease for an apartment? Or if the landlord never mentioned anything about pets? I’m looking for a new place but everywhere I look they don’t want dogs not even small ones 🙁 and my dog is a tiny bishon/Maltese he’s 9 years old and has been with us since he was 3 months old 😥 I don’t have much time until this month ends to find another place