Syniptc 



115 



process. Cardiac weakness manifests itself in a pounding apex 

 Ijeat and in a weak to filiform pulse which may be increased 

 to double the normal number or more per minute. There is 

 then also collapse, cyanosis, the veins are over-distended and 

 a venous pulse is noted. These circulatory disturbances are 

 caused partially by the weakening effect of bacterial toxins on 

 the vessel walls. 



Another very dangerous complication is suppuration or 

 gangrene of the pulmonary tissue, particularly in horses. The 

 advent of this complication is sometimes announced by a chill 

 and by elevation of the temperature which may even have been 

 falling; then there 

 is continuous or re- 

 mittent fever to the 

 end. Disintegra- 

 tion of pulmonary 

 tissue is announced 

 unmistakably by 

 the onset of signs 

 of cavity - forma- 

 tion (tympanitic 

 sound persisting 

 long in a circum- 

 scribed place, 

 possibly asso- 

 ciated with metal- 

 lic sounds and am- 

 phoric breathing ) , 

 and by the appear- 

 ance of a disagree- 

 able sweetish smell 

 of the exhaled air. 

 The symptoms of 

 septicemia likewise 

 become manifest. 

 Under these condi- 

 tions improvement 

 occurs only very 



exceptionally. (Abscesses of the lung may break into a bron- 

 chus and may then heal completely. — Johne.) 



Pleurisy is seen comparatively frequently; its occurrence 

 as a complication is, however, quite variable. Tenderness of 

 portions of the thoracic wall situated over the affected pul- 

 monary areas, in connection with considerable acceleration of 

 the pulse (Fig. 16), sometimes alone suggest the occurrence 

 of a complicating pleurisy. Friction sounds are heard fre- 

 quently or an al)undant fluid exudate is formed in the thoracic 

 cavity. The signs of pneumothorax (metallic sound, splashing, 

 sudden respiratory difficulties) may occur in gangrene of the 



Fig. 16. Fever curve in croupous pneumonia wUhco- 

 existituj fibrinous pleurisy in a horse. Increased pulse 

 frequency from tlie beginning of the disease. 



