What advice are you looking for exactly? Have you given him the broccoli? How is he? Why would you need critical care?

Broccoli and cabbage can be gas inducing in some bunnies. So you’ll have to introduce very slowly and monitor the poops. I personally never feed either of those just because I don’t want to take a chance (Bombur gets stasis easily). Critical Care does look green even when it’s fresh, so bear that in mind for if you eventually get another one. It’s always safe to have it on hand though, You never know what may happen

Here’s a broccoli leaves photo: broccoli

A tiny piece of broccoli is tolerated by most buns, but can induce gas in others. So as A&B says, start with a small piece. It is a cabbage type plant, and some buns can be sensitive to the cabbage family of plants, but it’s not toxic or anything.

If a bun do get gas, baby gas drops (simethicone) would be better than Critical Care, but it’s always good to have both CC and gas drops in your bunny medicine cabinet =)