Respiratory infection of cattle associated with myxovirus parainfluenza 3

Abstract

Extract

Myxovirus Parainfluenza 3 (PI3) infection of cattle appears to be common as serological surveys in several countries have shown a high incidence of specific antibody in the serum of otherwise normal cattle. These findings have been interpreted as indicating that, in many cases, infection was subclinical. In New Zealand, Fastier and Hansen (1966) also found serological evidence of previous infection in many cattle in the absence of clinical illness. Presence of passively transferred antibody in calves up to the fifth or seventh week of age suggested that seropositives in many herds of older cattle might reflect active infections acquired originally under the cover of a waning passive immunity.