Sneezing chickens HELP

[smoore7489]

A few weeks back I had one of my new hens start sneezing and LOUD. I contacted a friend who suggested corid, but it did not do any good and she passed. I knew she needed antibiotics but didn't know which ones to look for (off label or over priced on sell sites). This was weeks ago. Now I have another one with the same symptoms and one found dead who had zero symptoms. I'm positive I need to administer antibiotics but unsure on what to look for or dosages. Please, can someone offer advice?! This is primarily effecting my young 1st year hens, my older hens who are 3-4 yrs old don't seem effected yet. TIA!

 

[Wyorp Rock]

A few weeks back I had one of my new hens start sneezing and LOUD. I contacted a friend who suggested corid, but it did not do any good and she passed. I knew she needed antibiotics but didn't know which ones to look for (off label or over priced on sell sites). This was weeks ago. Now I have another one with the same symptoms and one found dead who had zero symptoms. I'm positive I need to administer antibiotics but unsure on what to look for or dosages. Please, can someone offer advice?! This is primarily effecting my young 1st year hens, my older hens who are 3-4 yrs old don't seem effected yet. TIA!

Can you get a video of the sick hens? Upload video to youtube and provide a link.
If video isn't possible, photos may be helpful.

Is the only symptom sneezing? Any mucous, facial swelling, bubbles in the eyes, discoloration of the comb and/or legs, bad odor, lesions inside the beak?

You are right that Corid wouldn't help with respiratory disease. It's a Coccidiostat, not an antibiotic.
As to which antibiotic to treat with, it's best to know what you are dealing with. If it's a bacteria like disease like Mycoplasma, then Tylan can treat symptoms. If it's Infectious Coryza, then a Sulfa Antibiotic would be better suited to treat symptoms. If it's viral, then it would need to run it's course, but sometimes an antibiotic is need to treat symptoms of secondary bacterial infection.
Getting some testing to find out what you are dealing with is the best way to know how to treat symptoms. Sometimes that's not possible and you may need to just treat to see if symptoms improve. If that's the case, then Tylan is probably your best bet. Do keep in mind that abx treat symptoms. Respiratory illnesses make birds carriers for life and they can continue to become symptomatic periodically. Certain ones can also be passed into the embryo of hatching eggs. It's best to keep a closed flock. No birds in or out.

Where are you located in the world?
How long did you have the New Hen before she got sick?
Your 1st Year hens, did you raise them with your 3-4yr old hens, they have been with you since chicks?
Where did the new hen(s) come from? All the same place?