If you cull all the ones who look sick, you may as well cull the entire flock. By now they are all exposed to the virus if they have been in a barn or a coop for over a few days. Birds in cool weather will buddy up on the roost and eveyone usually ends up with the virus.
I am having the same problem. It got very cold and a number of the birds came down with a "cold". If you do not get the bacterial discharge that really smells bad you do not have Coryza. All chickens stink to a certian extend, they just smell like a chicken, especially free range chickens, they are into everything. Chickens even pick up other chickens poop off the ground, it is just a part of being a chicken and this is actually beneficial if everyone is disease free.
Be sure that you have WORMED your birds !! The worms will kill your birds if they are going through a virus in the population. I would even go to the extent of worming before I treated for the virus.
I lost a nice hen just this day to the disease going through my flock. She just got very weak and I held her this evening until she passed. I knew she was struggling, it was pretty sad. I use vet Rx on her for several days. She was really too far gone to save.
Tommorrow I am going to start the Antibiotics. Everyone has gone through the virus now and I am fighting the secondary bacterial infections. Closed eyes, a bit listless and a little respiratory problems.
I am going to use Sulmet this time around. I used tetracyline last time and am not a fan of using the same antibiotic over and over agian for fear of resistance. I have not used antibiotics until it is necessary. This time I let the disease go completely thorugh the flock. Those who are not sick have built up an antibody to the virus and are doing pretty well. It can tell who had it last time and who did not.
My flock has been closed now since the last go around. I only will end up with carrier birds that survive this. Non one out, no one in.
I wormed my flock two times a few weeks ago. I have a few with closed eyes and continual sneezing. So it is now time to treat. I really have no choice EXCEPT to cull and I do not eat my birds, only collect eggs and enjoy the antics.
My nice Jungle fowl roo was VERY sick the last time. He was sick again for a very short time and is now running on the property. I am glad I did not cull him, but I will never sell him.
So, it is up to you to cull. You will more than likely have to start over and even then you are not immune from some bird infecting your flock all over again.
Treat your sick birds with Ver Rx until every one is infected. Wait to see who survives and builds resistance then treat with a good antibiotic and do this correctly. Worm first, I have found this saves many a bird.
Antibiotics alone are not going to save your birds. They have a virus and unless you have vaccinated for the virus, they are just going to get sick. It is up to you to cull. BUt, I do think you will be killing a lot of your flock. Coryza is a fairly fatal disease from what I understand. So is Marek's and so is Cocci if not treated from the onset. ILT is fairly easy to diagnose becuase the symptoms are unlike other respiratory diseases. CRD is a general term for a virus that is unknown, but presents like all respiratory virus. If you suspect Coryza you really need to isolate the infected birds and treat them with intensity. Again if you have a bacterial smell, you probably have Coryza, if not you have a really bad respiratory disease that may by treatable. I would cull a Coryza infected bird, if after a few days of treatment/isolation they do not improve.
It is so very hard to diagnose what virus you have, but there are certain symptoms that will tell you when it is really serious. I am guessing I am dealing with CRD.
I have found this URL link extremly informative and helpfull.
http://edis.ifas.ufl.edu/PS044#
It has the chicken respiratory diseases and SYMPTOMS. Go to the bottom of the page for lots of information.
I have decided to put a table on repiratory disease symptoms on my BYC page. I have done this and you can visit this. I called it
Respiratory disease sypmtoms and it is my second page.
Good Luck
