Does condo owner have to give property manager key to unit?

I own a Condo in Brooklyn, NY. We have lived there for 6 1/2 years. The property manager is asking everyone in the building for a key to their unit in case of an emergency. He said it was in the condo books, but I never saw that. I wouldn't want anyone to have access to my condo. I have a dog. What do you think? Can he make us do this? Thank you very much for your advice.