INFECTIOUS DISEASES. 99 



PYEMIA. 



Define pyaemia. 



It is a systemic disturbance, due to the absorption of septic 

 matter from a wound, and characterized by the formation of mul- 

 tiple foci of suppurative inflammation (metastatic abscesses), in 

 various parts of the body, and accompanied by certain systemic 

 symptoms. 



What is the aetiology? 



It is caused by pus microbes, just the same as septicaemia, but 

 they seem to be in groups and become lodged in various organs, 

 and set up foci of suppurative inflammation, and reproduce in 

 greater numbers. 



The microbes producing pyaemia are several. The most com- 

 mon is the staphylococcus pyogenes aureus or albus; the strepto- 

 coccus pyogenes; bacillus pyocyaneus; bacterium coli commune, 

 and no doubt any pus-producing microbe. 



What is the morbid anatomy? 



The blood is characterized by a tendency to coagulate spon- 

 taneously (wherever the blood-current is slow). Multitudes of 

 micrococci are found in the blood and on the walls of the vessels; 

 venous thrombosis and embolism are essential features of this 

 disease. 



These emboli become lodged in the small arteries of different 

 organs, and lead to the formation of abscesses. Metastatic ab- 

 scesses are found in the lungs, liver, spleen, muscles, kidneys, heart, 

 and brain. 



In a general way we may say that the blood becomes directly 

 affected by the veins, whereas, in septicaemia, it comes indirectly 

 through the lymphatics. 



What are the symptoms? 



Well-marked symptoms are shown; first, a chill, followed by 

 fever, with a gradual rise of temperature from 102° to 104° F. 

 The chills of pyaemia occur irregularly, and the temperature is 

 higher than in the sweating stage. 



The pulse is frequent, small, and intermittent. The conjunc- 

 tiva becomes yellow, there is loss of appetite, thirst, diarrhoea, the 

 animal becomes dull, the respirations are hurried and shallow. 



