Bovine Pinkeye

Etiology and Pathogenesis

Abstract

Significant advances have been made in the clarification of the etiology and pathogenesis of bovine pinkeye. The well established role of Moraxella bovis as a causative agent of the disease is now further clarified by an understanding of predisposing causes commonly involved in this disease. Of importance are ocular mycoplasmal infections, particularly by Mycoplasma bovoculi which clearly enhance the colonization of cattle eyes by Moraxella bovis. Dual infections are always seen in natural cases of the disease, and further, dual experimental infections will reproduce pinkeye, even if low doses of these organisms are deposited on the unaltered corneas of experimental calves. Additional requirements to produce pinkeye experimentally are the use of strains of M. bovis expressing adhesive pili and a surface- bound hemolysin. In vitro models and mouse pathogenicity models developed to study these phenomena add to our knowledge of the pathogenesis of this disease.