Lost an entire batch of chicks and nothing I did saved them

[LockChicks]

I just wanted to wish you some peace in your nightmare that you went through. The worst thing is not knowing and I've beaten myself up plenty time and time again when I can't fix one of my chicks. Really sorry you went through this.

 

[Wyorp Rock]

sold me 8 chicks ranging in age from a week to a month, and a dozen eggs.

Two days later, two wake up with swollen eyes. Like their eyes are swollen shut. I gave them the last of my remaining denagard stash from show season, (only like a teaspoon), and then start oral Tylan 50. I also put Tylan in the water. By day 2, the initial two chicks are now wheezing and gasping, i continue medicating. More chicks develop the exact same symptoms. I buy LA 200, and put that in the water. The month old chick, my favorite, becomes symptomatic, and in desperation, I even start doing IM injected tylan with her. Denagard is of course completely unavailable locally, so from the onset of first birds symptoms tuesday, my denagard arrives thursday night.

I put them in with my homegrown chick, and he was one of the last to develop symptoms, and also died

Sorry for your losses.

Having a necropsy/testing will give you some answers. https://www.metzerfarms.com/poultry-labs.html

You mention that you had "remaining" denagard (Tiamulin) from show season. Do you have respiratory disease within your existing flock(s)? Generally most people do not keep Denagard on hand unless they have respiratory disease in the flock.

Since the ABX did not seem to help with the symptoms, then you may be dealing with a virus.
If you show birds, then it's best to find out what this is so you don't unwittingly take carrier birds to shows and continue the spread.