I have a question, I read somewhere on a different thread about some one that lost a hen and they think its gag worm, what exactly is gag worm?
Do you mean gape worm? Gape worm is a parasite that invades the trachea of chickens, it is called gapeworm, since a bird that is heavily infected will "gape" since the worm is blocking the chicken's airway. The birds will eventually die of suffocation, starvation, or weakness.