Hiya Beth, and welcome aboard! You'll find that things move slower here than BPN, but the advice, learning and general atmosphere are wonderful.
Nice relaxed pose, especially for a cat named Itchy! I might be tempted to go vertical or square to bring the focus to the front feet and face.
Portraiture, unlike nature photography (IMO), is a lot more open to creative interpretation and manipulation. I don't have a problem replacing backgrounds, removing shadows, swapping ears, or even heads at all.
I do it quite often to improve composition when going from a mastiff to a chihuahua without changing all my props around between shoots. At every event, I take a few "blank" shots of my set from the angles I'm likely to be shooting just in case I need to do some pixel magic.
All that said, my life is a thousand times easier after a big event if I don't have to do all that.
As far as start-up equipment goes, for cats and other smallish critters, if you have some clean sheets, you have some backdrops.