Passive smoking and pets?

I smoke.
Now, whenever i get visitors or when i am visiting someone else, i ask the person(s) (t)here if they mind if i smoke.
And when the question whether we want a baby in the future comes up, me and my girlfriend both agree that the only good thing to do is to quit smoking.
The best thing to do would may be to even quit before conceiving?
We all know of course (through logic and/or scientific research) that passive smoking (or second hand smoke) is bad.
For babies as well as for adults.
But here is what i am thinking lately: i have a pussycat living with me in the house, and i feel sometimes a bit guilty, since she is inhaling second hand smoke as well.
What is your view on smoking and having pets?