Introduction

A viral disease of pheasants, partridges, wild birds, chickens, turkeys, ducks and pigeons having a high morbidity and high mortality. It is transmitted between birds by pecking and by mosquitoes. These conditions currently only occur from northern South America to North America. The natural hosts are wild birds and rodents. Horses are also seriously affected.

Signs

• Nervous symptoms.
• Ataxia.
• Paresis.
• Paralysis.
• Flaccid neck.
• Circling.
• Tremors.
• May also be asymptomatic.

Post-mortem lesions

• No gross lesions.
• Microscopic lesions not pathognomonic.

Diagnosis

Isolation in mice, TC, and CE, ID by VN, COFAL.

Treatment

None.

Prevention

Protection from mosquitoes, control cannibalism. Vaccinate at 5-6 week.