no DISEASES OF THE HOG. 



CHAPTER XIX. 



RHEUMATISM. 



This is a very common disease among pigs, espe- 

 cially young ones. It is a constitutional disease 

 attended by a peculiar irritation or it might be 

 called an inflammation to which all parts of the 

 body are liable, but it is found most frequently in 

 the hind legs. It is found in two forms, muscular 

 and articular, the former when it affects the tissue 

 of the muscle, and the latter when it affects the 

 structures composing the joints. The nature of 

 rheumatism is not well understood. The profes- 

 sion is divided as to what it really is; some say the 

 offending matter is lactic acid, others that it is 

 uric acid, but none of these substances have been 

 found in sufficient quantities to cause it. Wood 

 says of this disease: "All that we know of the 

 real nature of this disease is that it is peculiar, and 

 that it owes this peculiarity, not to the character 

 of the cause, but to some unexplained condition of 

 the system called the rheumatic predisposition or 

 diathesis. I am inclined to the opinion that this 

 diathesis is in itself a morbid state, in fact, the 

 true disease, and that the irritation and inflamma- 

 tion by which it is recognized are merely syiDp- 



