It’s too late for us now, but if I had another two chickens die in close succession, I’d consider rushing the bodies off to one of the California Animal Health and Food Safety’s labs run by the University of California Davis’ School of Veterinary Medicine.
A Root Simple reader who is a veterinarian tipped us off to this service. You don’t need a veterinarian (though you might need one to help interpret the results) and the service is free to those with less than 1,000 birds. All you need to do is get the body, as soon as possible, to one of four labs in either Davis, Turlock, Tulare or San Bernardino.
The backyard flock submission form is available at: http://www.cahfs.ucdavis.edu/submission_forms/index.cfm. The addresses of the labs are on the form. I’m sure that many other states offer similar services. Call your local Extension Service for details and leave a comment if you know about your state’s testing programs.