Hi looking for the best way of introducing our 2 sister cats to new puppy we are getting n vice versa. Our cats are 7 years old n sleep on our beds upstairs. I am going to put up stair gate at bottom of stairs so puppy cant get up. when we are out the puppy will be in its crate. Should i still let cats have run of house or seperate them for few days? Should i keep puppy on lead at first around cats? I love our cats dearly n want to do the best by them and our new puppy.