Avian paramyxovirus type 1 infection in pigeons: recent changes in clinical observations.

Since its first appearance in 1984, avian paramyxovirus type 1 has remained an enzootic disease in racing pigeons on Long Island, New York. The clinical presentation of the disease in the autumn of 1987 suggests a decrease in the severity and incidence of neurological signs, with the chief complaint being watery droppings accompanied by poor racing performance. Diagnosis is based upon serology, using hemagglutination-inhibition tests with Newcastle disease or paramyxovirus type 1 virus.