GENERAL DISEASES. 105 



Fatty degeneration, commencing in the central portions, 

 is the main cause of the difference between the two. 



Scrofula. — Is a constitutional condition, characterized by 

 a great susceptibility of certain tissues to become the seat 

 of chronic inflammation, the products of which have but 

 little tendency to become absorbed, but rather tend to 

 infiltrate and accumulate in the tissues. 



They thus interfere with the circulation, and so lead to 

 retrogressive and caseous changes ; and as there is but 

 little tendency to the formation of fresh blood-vessels, there 

 is no organization of the new growth. These changes are 

 in a great degree to be attributed to the low condition of 

 vitality of the tissues, and to the peculiar character of the 

 inflammatory products. 



Relation of Scrofula to Tubercle.— Owing to the similar 

 microscopical appearances of scrofulous and tuberculous 

 lesions, as well as to the presence of the Bacillus Tubercu- 

 losis, in what appear to be simply scrofulous products, 

 these two aff'ections have been regarded as identical, and 

 scrofula has been looked upon as not merely due to in- 

 herited or acquired liability to simple chronic inflamma- 

 tions. 



Now, although tubercular changes are especially liable to 

 occur in scrofulous patients, and though the bacilli may be 

 found in scrofulous lesions, yet the latter may be regarded 

 merely as simple chronic inflammations, aff'ording a suit- 

 able soil for the growth of the germ. 



Scrofula and Tuberculosis, though of frequent occur- 

 rence in cattle, are not commonly met with among horses. 

 In the localized form, tubercle in the horse is said to occur 

 in the lungs, pleura, and glands of the abdominal cavity ; 

 and many cases of well-pronounced arthritic disease in 

 young horses are regarded as decidedly scrofulous in nature 

 by Professor Kobertson. This form of arthritic disease is 



