Clinical classification of pneumonias in cattle

Abstract

More beef cattle develop and subsequently die from respiratory diseases than from all other causes. In cattle under close confinement respiratory diseases cause 75% of the illnesses and 64% of the deaths. Pneumonias constitute 75% of the diagnoses of respiratory diseases.

Epizootics of respiratory disease are recognized by cattle owners who request and expect accurate diagnosis, but veterinarians experience difficulties making definitive diagnoses because of the similarity of signs in sick cattle and the many viral and bacterial pathogens recovered at necropsy.

Since a specific clinical diagnosis may be difficult to make in the field, the purpose of this paper is to simplify diagnoses by recommending a classification of pneumonias based on pathogenesis where major signs in each pneumonia are different and distinguishable.

To clarify this classification, each pneumonia will be discussed in relationship to etiology, pathogenesis, pathology, and clinical signs.