As the virus can breach the blood-brain barrier and result in damage to the brain and spinal cord, neurological disease is the predominant presentation among horses showing clinical signs. These can include non-specific signs such as inappetence, some cases may demonstrate a fever and others may commonly be subclinical. Encephalitis ranges in severity from mild depression to head pressing and a state of drowsiness. Additional neurological signs can include behavioural changes, facial twitching, impaired vision, inability to swallow, heightened sensitivity, muscle fasciculations, weakness (paresis) or paralysis of front and/or hind limbs, loss of bodily function (ataxia), aimless wandering, recumbency, coma and death.
