Aww poor Woofie, sorry to hear he's a bit under the weather
No advice for you I'm afraid, but hope he feels better soon. Chloe eats a lot of grass, but I think that's just cos she likes it
She is sick occasionally in the mornings, that slimey watery kind of stuff, but I never worry if she's still bouncing around. I guess I may be be slightly more concerned if she'd been winging as well, like you describe Woffie doing, but I bet he's just got a bit of an upset tum, and is feeling slightly uncomfortable.
Fingers and paws crossed he's all better very soon