PRINCIPLES OF VETERINARY SURGERY 653 



patient is unable to keep the tongue within, and as a result 

 it becomes the seat of wounds that show no incHnation to 

 heal. Deafness may be observed, but when the patients 

 reach the stage just described they are generally slaught- 

 ered, or found dead in their sty. 



Previous mention that the disease is preceded by arthri- 

 tis necessitates the statement that the facial lesions and the 

 arthritis may develop absolutely independently of each 

 other. Whether the joint localization is due to microbian 

 externalization, cannot be affirmed until the provocative 

 micro-organism of the facial lesions is found in the articular 

 cavities. 



PATHOLOGICAL ANATOMY.— The only altera- 

 tions concerned in the evolution of the disease are confined 

 to the head. Besides the articulations, — and they are not 

 always afifected.^the remainder of the skeleton is normal. 

 The spinal column, the ribs, the pelvis and the long bones 

 are not implicated. The physiognomy of the facial tumor 

 resembles the tumor of rhinoscleronia of man as much as 

 two lesions in different species can. The descriptions of Car- 

 nil and Alvarez in "Archives of Physiology" apply, without 

 modificatioin, to snififling disease of the hog. 



The nasal cavities, the septum nasi, the turbinated bones, 

 and the ethmoid cells are absolutely free from altera- 

 tions. There is no lesion in these ^ructures. The mucous 

 membrane is normal, smooth and free from inflammation 

 or coating of any kind. This authenticated fact is not with- 

 out interest from the standpoint of the seat of inoculation. 

 The new tissue is formed at each side of the nasal fossae and 

 below them, and its extension compresses, contracts, and 

 displaces them from below upwards. They are all the more 

 narrow toward the posterior nares. The transformation of 

 the nasal cavities into narrow cell clefts sufficiently explains 

 the difficult respirations. 



