EPIDEMIC TREMOR, AN ENCEPHALOMYELITIS AFFECTING YOUNG CHICKENS

Area of Science:

• Veterinary Neurology
• Avian Pathology
• Infectious Diseases

Background:

• A new disease affecting young chickens with distinct neurological symptoms has emerged in New England.
• The condition presents with tremors and ataxia, impacting morbidity and mortality in commercial flocks.

Purpose of the Study:

• To describe the clinical and pathological features of this novel avian disease.
• To investigate the etiological agent and its transmission characteristics.

Main Methods:

• Clinical observation of affected flocks and individual birds.
• Intracerebral inoculation of healthy chickens with affected brain and spinal cord tissue.
• Serial passage studies, infectivity agent stability tests, and filtration experiments.
• Histopathological examination of nervous tissue and visceral organs.

Main Results:

• The disease was successfully reproduced through intracerebral inoculation, with increased susceptibility in serial passages.
• The causative agent survived in 50% glycerine for 69 days and passed through sterile filters, indicating a non-bacterial nature.
• Characteristic microscopic lesions included glial nodules, perivascular infiltration, and neuronal degeneration in the central nervous system.

Conclusions:

• A new, presumably viral, neurological disease affects young chickens, characterized by tremors and ataxia.
• The disease is transmissible via intracerebral inoculation and associated with specific neuropathological findings.
• Further research is needed to identify the specific infectious agent.