144 Pyobacillosis of Hogs. 



consists in a specific chronic granular suppurative inflammation which 

 sometimes is confined to the digestive tract, at other times afifeeting 

 also the mucous meml)ranes of the air passages and especially the 

 lironclii, in which case the lungs develop a catarrhal suppurative or 

 a purely suppurative inflammation. With the aflPection of the mucous 

 membrane an exudative inflammation of the serous membranes be- 

 comes associated and a generalization of the suppurative processes 

 may also take place. 



The changes, however, do not correspond with those pathological 

 processes which have customarily and undoubtedly with justice been 

 considered as swine plague lesions. Acute catarrhal croupous or 

 necrotic pneumonia, such as is observed in acute outbreaks of pure 

 swine plague, as well as in a more frequent mixed infection with hog 

 cholera, has in no case been produced in the above experiments. These 

 facts have been pointed out by Olt, Casper and Ostertag (the changes 

 which were indicated as such were always atelectatic). The bacillus 

 pyogenes suis exerts in all cases purely pyogenic properties. 



According to Olt the disease caused by the pyo-bacillus and desig- 

 nated by him as "pyemic cachexia of hogs" (the name pyobacillosis 

 was suggested by Liipge) occurs in the majority of cases as an in- 

 dependent afifection, but also in association with, or as a result of 

 other infective diseases. Contrary to this Ostertag maintains, without 

 disputing the independent occurrence of pyobacillosis, that most eases 

 of the affections of the lungs described by Grips are chronic affections 

 of swine plague caused by ovoid bacteria. He claims that in the course 

 of the disease the Grips bacillus as well as other bacteria may localize 

 especially in the bronchial mucous membrane, and this is the more 

 possible as it is known that this organism occurs as a saprophyte in 

 the upper air passages of healthy hogs. The primary etiological part, 

 the ovoid bacterium, in pneumonia of pigs has been authoritatively 

 established in accordance with the description on page 189. Considering, 

 however, the fact that the pyo-bacillus occurs in pure cultures only 

 in metastatic abscesses, while in the pneumonic lungs it is always 

 present in association with other pathogenic bacteria, it probably takes 

 only a secondary part in the lung affections of hogs. In such cases 

 it is the cause of severe changes, especially of extensive suppurations. 



The pyo-bacillus exerts a similar action in the suppurative 

 processes of ruminants. According to the investigations of Poels, 

 Kiinnemann, Roux, Holth and Olt it occurs in inflammation of different 

 organs in cattle (Poels found the organism in 38 out of 56 cases). 

 However, it is mostly present in association with staphylococci, 

 streptococci, colon bacilli, necrophorous bacilli and other bacteria. It 

 occurs especially in cases of peritonitis caused by foreign bodies, in 

 bacillary pyelonephritis, metritis, to which inflammation of the valves 

 of the heart may be added; further in arthritis in calves, various 

 broncho-pneumonias in young as well as in old animals; finally in 

 mastitis, especially in those cases Avhich are associated with septic 

 and catarrhal metritis (according to Holth the presence of the bacillus 

 pyogenes is especially indicated by a thin milk-like secretion of the 

 udder with dense yellow irregular flakes; further by a purulent fetid 

 secretion). As a causative agent of mastitis it has been established 

 in goats (Dammann & Freese, Olt) and in sheep (Olt). Olt also found 

 the organism in broncho-pneumonia of lambs and sheep in which 

 especially the terminating bronchi were in parts almost entirely ob- 

 structed with masses of bacilli. 



