@Miss Lydia no there was no bulge but thank you he seems better this morning. @goldenflight thank you as well, my husband said the same thing, it seems that was it. I think me freaking out clouded my better judgement.
@chickens really I added a bit more grit to their diet and thank you also.
My Pekin duckling is around 2 months old and I noticed something strange on his neck. When I picked him up to check it he three up all over the place. He's drinking water fine but I'm terrified, somebody please if you can think of anything.