PRINCIPLES OF VETERINARY SURGERY 599 



are accurate and have thrown some light on the pathogene- 

 sis of the afifection. 



The disease is known to rage in various locaHties. In 

 1892 it ravaged Le Berry, La Sologne, La Brie and all of 

 the Eastern region of France. It is constant in some dis- 

 tricts, and the intensity varies with dififerent years. In 

 some years the cases are isolated, while in others they are 

 so numerous that it assumes the character of an epizootic 

 disease. 



ETIOLOGY AND PATHOGENESIS.— The condi- 

 tions under which the disease appears are numerous. In 

 spite of our knowledge of them the pathogeny has not been 

 settled. The following is an enumeration of the etiological 

 conditions and the pathogenic theories : 



It must first be remembered that osseous cachexia is an 

 afifection of nutrition reflected chiefly on the osseous tissue 

 which becomes demineralized. Every influence that is cap- 

 able of causing vitiated and imperfect nutrition has been 

 dwelt upon as productive of the disease. These are : Bad 

 hygiene, defective alimentation and over-work. Females 

 during the period of gestation and lactation, are particu- 

 larly predisposed. This fact is acknowledged by all writers, 

 and many show that the disease often appears soon after 

 parturition. The dififerent opinions advanced as to the me- 

 chanism of osseous cachexia are as follows : 



1st. It is the consequence of the ingestion of materials 

 insufficient for the nutrition of the skeleton, or the exces- 

 sive elimination of the elements indispensable to it. This 

 is the theory of inanition, gestation, lactation, etc. 



2nd. It is due to a dissolvment of the calcareous salts, — 

 the lactic acid theory. 



3rd. It is due to a microbian agent which causes in- 

 flammatory disturbances, — the microbian theory. 



The preponderating part played by alimentation and in- 



