Atypical interstitial pneumonia in cattle.

Atypical interstitial pneumonia is described as two clinical syndromes in young cattle. One syndrome occurs in animals which have clinical evidence of pneumonic pasteurellosis, responds initially to treatment for one to two days and then develops acute signs of atypical interstitial pneumonia. The second syndrome involves acute respiratory distress in young calves due to atypical interstitial pneumonia with antecedents of enzootic pneumonia. The postmortem lesions are described along with discussion of the possible pathogenesis of the condition and treatment.