Abstract
Effects of gaseous ammonia on Mycoplasma pulmonis infection in mice and rats were investigated with special reference to growth of the organism in the respiratory organs and formation of pneumonic lesions. Multiplication of the organism was enhanced in both mice and rats exposed to 50 and 100 ppm ammonia, but the growth enhancement of the organism was not evident in the animals exposed to 20 ppm ammonia. The enhanced multiplication of the organism was especially remarkable in the lung of mice, showing a difference of about 104 organisms/g lung tissue between the exposed and unexposed mice. However, no formation of pneumonic lesions was observed in exposed and unexposed groups of both species of animals.