Avian Vacuolar Myelinopathy (AVM): Overview

 What is Avian Vacuolar Myelinopathy

Avian vacuolar myelinopathy was first recognized in 1994 when it killed 29 bald eagles in Arkansas. Since then, AVM has been confirmed or suspected in the deaths of at least 90 bald eagles in Arkansas, Georgia, North Carolina, and South Carolina. AVM also is responsible for hundreds of American coot deaths and has been detected in other avian species, including mallards, Canada geese, great horned owls, and a killdeer. The cause of AVM remains undetermined despite extensive diagnostic and research investigations by several state and federal wildlife resource agencies and universities. However, a natural or manmade neurotoxicant is suspected because there has been no evidence of viruses, bacteria, prions, or other infectious agents, and the lesions are consistent with toxicosis. To date, AVM has not been confirmed in mammals, and it remains unknown whether the cause of AVM could affect humans.

Source: SCWDS Briefs

 Overview

Birds with AVM may fly erratically or not be able to fly at all; they may stagger and fall when walking.  They may swim listing to one side or swim in circles in apparent attempt to right themselves.  The disease may also have more severe implications; AVM can result in paralysis and death of affected birds.  Interestingly, there have also been birds diagnosed with the disease, based on lesions in the brain, without any outwardly apparent physical abnormalities.  The list of affected species continues to grow, but remains confined to wild birds including bald eagle, American coot, great horned owl, killdeer, Canada goose, mallard, ring-necked duck, and bufflehead.  AVM has killed over 90 bald eagles in AR, GA, NC and SC.  It has also resulted in the deaths of hundreds of coots.

Source: Fish and Wildlife Services, North Carolina - Ecological Services