178 SOUTHERN rORK TRODUCTIOX 



can do little but harm in spite of his probably false 

 reputation. 



Swine diseases. — In a general way the diseases of 

 swine may be divided into three main groups. The first 

 of these is the result of an infection of some sort and may 

 be either infectious or contagious, depending upon the 

 method of transmission from one animal to another. In 

 addition to diseases due to microscopic organisms there 

 are certain other diseases due to macroscopical organisms. 

 Such diseases as these are conveniently classified as para- 

 sitical diseases. There are also a number of diseases that 

 can be classified as surgical, since surgery is involved in 

 their treatment. As a good example of surgical diseases, 

 we might refer to hernia or rupture. In addition to this 

 classification, diseases are frequently classified into 

 groups according to the organs, parts, or systems 

 affected. Among these groups we find diseases of the 

 circulatory system, digestive system, excretory system, 

 locomotor system, nervous system, reproductive system, 

 respiratory system and diseases of the skin. 



Circulatory system. — The circulatory system involves 

 the heart and the blood vessels carrying blood to the dif- 

 ferent parts of the body and returning it to the heart. 

 Diseases affecting the circulatory system are generally 

 the indirect result of tmhealthful conditions in other parts 

 of the bod3^ and this becomes one of the first systems 

 affected in general disease. Aside from the matter of 

 pulse rate and strength and other minor diseases of the 

 system, there are two diseases affecting this system that 

 are not uncommon in the swine herd. The first of these 

 is septicaemia or blood poisoning, and the other is fatty 



