CHAPTER XXVIII 



INFECTIOUS DISEASES COMMON TO THE DIFFERENT 

 SPECIES OF DOMESTIC ANIMALS 



Septicaemia and Pyaemia. — The term commonly used in 

 speaking of simple septicaemia and pyaomia is blood poisoning. 



These infections diseases are caused by several different 

 species of bacteria that gain entrance to the tissnes by way of 

 wounds. The bacteria that cause pyaemia are transferred by the 

 blood stream to different organs and prodnce nniltiple abscesses. 

 Tn septicaemia, the bacteria may occur in immense numbers in 



Fig. 97. — Stap/iyluco^cus piiogenes. Fig. 98. — Streptococcus pyogenes. 



the blood and produce a general infection of the tissues, causing 

 a parboiled appearance of the liver, heart, voluntary muscles and 

 kidneys, and enlargement of the spleen. The two forms of infec- 

 tion are often present at the same time. 



The forms of bacteria that may cause blood poisoning are 

 the Staphylococcus pyogenes aureus and albus (Fig. 97), Strep- 

 tococcus pyogenes (Fig. 9S), BarUlus pyocyaneus. Bacillus coli 

 communis, and the bacillus of malignant oedema (Figs. 99 and 

 100). The latter is included with the bacteria that produce blood 

 poisoning because it is a frequent cause of wound septicaemia. 

 Subcutaneous, punctured, lacerated, contused and deep wounds 

 without suitable drainage are the most suitable for the develop- 



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