I'm in Missouri and virtually every time I have a bird die, I ship it or hand carry it to the Mizzou diagnostic lab in Columbia. There is also a lab in Springfield but I think Mizzou's lab has better capability.
I raise very rare birds and it is imperative I know immediately what is going on in my flocks so I know a path forward. Doing otherwise, I could potentially lose more than half of all this breed that exists in north America.
Veterinary Medical Diagnostic Laboratory
University of Missouri
810 E. Campus Loop
Columbia, Missouri 65211-0001
Phone: 573-882-6811
Missouri Department of Agriculture Veterinary Diagnostic Laboratory
701 North Miller Avenue
Springfield, Missouri 65802-6460
Phone: 417-895-6861
By calling the lab At Mizzou, they will send you a FedEx label for shipping the bird.