Will this treat Gapeworm in chickens?

[Kiki]

Is it possible to harm the chicken if I give her too much? We figured out it was gapeworm a little too late and she’s on her last leg. I’d like to give her a double dose today just to get it in her system and then back to regular tomorrow. But I’m scared it might hurt her. Any and all advise welcome as a new chicken mom.

You are probably seeing your bird having trouble breathing and not gapeworm.