Early damages to lung capillaries in enzootic pneumonia of rabbits.

The present study is part of a series of investigations aimed at characterizing the "enzootic pneumonia" phenomenon in rabbits, both from the clinical-epidemiological and the pathophysiological point of view. All affected rabbits included in this study showed an acute injury to pulmonary microvasculature, similar to changes reported in pulmonary infections caused by Gram-negative bacteria. Similar alterations were not found in the control rabbits. The clinical and morphological findings revealed certain similarities between the Enzootic Pneumonia Syndrome of rabbits and Adult Respiratory Distress Syndrome (ARDS) of man. Therefore, it is suggested that, just as in the human syndrome, heterophils (PMN) are directly involved in the pathogenesis of the process. Many of the similarities noted between the two syndromes would make it possible to postulate the natural disease in rabbits as an eventual animal model suitable for extrapolating data to humans.