Avian Encephalomyelitis (AE) is a viral, transmissible neurological disease primarily affecting young chickens, though turkeys, quail, pheasants, and other gallinaceous birds may also be susceptible. Caused by the Avian Encephalomyelitis virus (AEV), a member of the Picornaviridae family, the disease is characterized by ataxia, tremors (notably of the head and neck), and paralysis, especially in chicks under three weeks of age. In older birds, the infection is often subclinical but can result in a transient drop in egg production and hatchability. Transmission occurs both horizontally (via the fecal-oral route) and vertically (through the egg). Control of AE relies on vaccination of breeder flocks to prevent vertical transmission and protect progeny through maternal antibodies.