UPDATE:
In late July I purchased two more very young chicks (3-days old) to replace the birds that died. The chicks were kept in the house away from the sick adult birds and I have been diligent about hand washing, never sharing feeders/waterers, etc. I'm sure I could have practiced even more intense biosecurity, but I haven't been sloppy or careless. The two chicks came from the same store as all the other sick birds. Fast forward 8 weeks and I lost one of the two chicks. Same symptoms as all the others except the paralysis was more intense and it took much longer for the chick to die. This one basically wasted away, unable to eat or walk.
This one was sent to the University of Missouri for Necropsy.
I am wondering if there is any need to address the "fungal hyphae in granulomas of the lung" which were noted as "consistent with Aspergillus". Should I treat the remaining chickens for Aspergillosis?
Below are the full Necropsy results:
AVIAN GROSS/HISTO EXAM
SPECIES: Avian
BREED: Chicken
AGE: 8 Weeks
SPECIMEN DESC: Dead Animal
GROSS COMMENTS: The body is thin and no fat is present. The crop is empty. The gizzard
contains grit. The ceca contain pasty dark green contents.
HISTOLOGIC EXAM: The sciatic and obturator nerves are infiltrated in several areas by
neoplastic lymphocytes. The lung contains a few granulomas. Fungal
hyphae are present in association with the granulomas. No significant
microscopic changes are detected in sections of brain, trachea, liver,
kidneys, heart, crop, pancreas, or intestine.
VMDL FECAL FLOATATION: No parasite ova seen
FINAL DIAGNOSIS: Lymphosarcoma of nerves
COMMENTS: This type of tumor in chickens is caused by infection with
Marek's disease virus (a herpesvirus). The neoplastic (tumor) cells
invade nerves and impair their function leading to weakness and
paralysis. In commercial chickens the disease is controlled by
vaccination of chicks in the hatchery. The fungal hyphae in the
granulomas of the lung are consistent with Aspergillus sp.