Avian Ganglioneuritis Study Guide

Overview and Clinical Importance

Avian Ganglioneuritis (AG), also known as Proventricular Dilatation Disease (PDD) or Avian Bornaviral Ganglioneuritis (ABG), is a chronic, progressive, and often fatal neurological disease affecting primarily psittacine birds (parrots). First recognized in the 1970s as "Macaw Wasting Disease," the causative agent, Avian Bornavirus (ABV), was not identified until 2008. This disease represents one of the most significant infectious neurological conditions in avian medicine and is a high-yield topic for veterinary board examinations.

The disease is characterized by lymphoplasmacytic infiltration of the ganglia and nerves, particularly affecting the myenteric plexus of the gastrointestinal tract, the central nervous system, and peripheral nerves. Clinical manifestations vary widely, ranging from primarily gastrointestinal signs to predominantly neurological presentations, or a combination of both.

Etiology

Causative Agent: Avian Bornavirus

Avian Bornavirus (ABV) is an enveloped, non-segmented, negative-sense, single-stranded RNA virus belonging to the family Bornaviridae within the order Mononegavirales. Unlike other members of this order that replicate in the cytoplasm, bornaviruses employ intranuclear transcription and replication, which contributes to viral persistence and immune evasion.