Ammonia inhalation toxicity in cats: a study of acute and chronic respiratory dysfunction

Twenty healthy conditioned cats were pulmonary-function tested and then exposed to 1000 ppm of ammonia gas for a 10-min period. Pulmonary function tests were repeated and lung samples for pathologic evaluation were taken on days 1, 7, 21, and 35 post-exposure. Two cats were housed with the experimental cats as untreated controls. Pulmonary function data were analyzed, statistically evaluated, and compared with the pathological observations. There was good correlation between the alterations in pulmonary function observed and the pathologic lesions found. According to our findings, and those of other investigators, the pulmonary dysfunction which results from ammonia gas inhalation is biphasic in nature. The acute effects of the initial insult, which can be fatal, are almost always followed by secondary effects which can result in debilitating, chronic respiratory dysfunction. This study has characterized an animal model which could provide techniques for preventing or modifying the course of the secondary damage of ammonia gas inhalation.