It is wrong to keep my pet a secret from my landlord?

My fiancée and I own a cat. By the rules of our apartment, we should notify our landlord and pay monthly pet rent and deposits. However, we keep a cleaner apartment than the majority of people without pets. If the cat’s not tearing up carpet and peeing on walls, I don’t feel I should pay more than say someone who is disrespectful of the property and causes more damage to the unit. Moreover, I recently heard firsthand from a group of experienced landlords that they prefer cleaner tenants with pets as opposed to straight up dirty tenants. So should I fess up and pay or not?