I have chickens from 4 1/2 months to 2 months & after some heavy rain that lasted several days few days later my chicks started sneezing at first nothing but a sneeze then I notice in one of them watery like came out of her nose it was clear that has stopped but the sneezing continues & now a few seem to have trouble or what looks like gasp for air every now & then ( like taken a deep breath). Farm store here told me to use duramycin 1/4 tsp per gallon then I read they should be getting 1-2 teaspoons a gallon now I've read tablespoon per gallon of water. What is the correct amount? I started with this on Monday then upped it on Wednesday. What should I do? HELP PLEASE! I've also read about giving Tylan 50? I don't know what I should be doing.