Chicken has been sneezing for a few weeks. Didn't think anything of it since all our chicks sneeze now and again. Went out to make sure all the chickens were in the coop one evening and noticed she can't breath laying down without gasping for air. Have started her on Tylan 50 but yet to see any results. How long does Tylan 50 take to start helping? Also, how would I know if possibly gape worm? Chicken still eats like normal and is active all day with chickens. Any help would be much appreciated.