Can I be just a cat sitter?

Yes you can, but other sitters have also offered other services. Not as many people need cat care so your business would be very slow.

I offer to watch both cats and dogs but get many more requests for cat-sitting. I suppose it depends on your service area but cats keep me extremely busy in mine!

Absolutely! Definitely state that in your profile about me section as well. Personally, for every 5 requests, one is always a cat LOL so it can be so different anywhere! Also, if you advertise and share your profile, make sure to state that you specialize in cat sitting.