You keep the collar on till the stitches come out, which is usually 10 days. You can take it off while they eat, and i always give them at least an hour without it on top of that, but it does depend on the cats, you have to supervise incredibly well with most of them!! They can eat, drink and sleep with them. IT is supposed to slip over their head, the bandage is to tighten it - if she wears a normal collar, you could slip the bandage through that to make sure she can't get it off. Good luck.