350 LUNGS AND PLEURA 



PNEUMO'MYCOSIS DUE TO ASPERGILLL 



The term pneumo-mycosis, or pulmonary aspergillosis, is used to denote 

 a condition due to the growth in the respiratory apparatus of a fungus 

 of the order aspergillus (family, Perisporue ; sub-order, Perisporiacece ; 

 order, Ascomycetes). 



In ruminants, as in all other animals, pulmonary aspergillosis 

 occurs accidentally, and may often pass unperceived, in spite of the 

 indications given by Lucet and Bournay regarding its development and 

 symptoms. 



It seems most frequently to be caused by Aspergillas niger and Asper- 

 gillus fumigahis, particularly by the latter, which, according to Eenon's 

 work, also appears to be the most pathogenic. It only develops in animals 

 whose respiratory apparatus is injured and is the seat of such lesions as 

 those of chronic bronchitis, bronchi- ectasis, and of parasitic lesions 

 or those containing cavernous spaces resulting from abscess formation, 

 etc., etc. 



The fungi, or more properly the spores, which have accidentally 

 penetrated into the respiratory channels germinate and develop in the 

 pathological dilatations, causing disseminated areas of pneumonia and 

 some mechanical disturbance, but not producing intoxication by liberating 

 toxins. 



Causation. Infection occurs through the air passages, in conse- 

 quence of the inspiratory current carrying spores of the fungi into 

 the ramifications of the bronchi, where they develop if the soil is 

 favourable. Development is favoured if the animals exposed to con- 

 tamination are in bad condition, or if, as sometimes happens, the walls 

 of the stables are not kept clean, and are covered with various forms 

 of fungi. 



Prolonged feeding on musty fodder may also favour respiratory in- 

 fection ; but it seems highly improbable that under ordinary conditions 

 infection can occur through the digestive tract. Infection of the lung 

 must also be regarded as exceptional, if one bears in mind the frequency 

 with which oxen are fed on musty or mildewed fodder and the small 

 number of accidents recorded. 



Symptoms. The symptoms are obscure, and pulmonary aspergillosis 

 is often only discovered on post-mortem examination. A cough is the 

 chief symptom. It is dry at first. Afterwards it becomes spasmodic 

 and frequent. 



Kespiration is difficult, dyspnoeic, effected only with effort, and some- 

 times even discordant. Expiration is sighing. 



Percussion reveals zones of partial or complete dulness when the 

 lesions are near the surface of the lung, which, however, is rare. 



