PRINCIPLES OF VETERINARY SURGERY 



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similar to the lesion of rarefying osteitis. New canals and 

 cavities are formed in the fundamental substance. In the 

 first period of osseous cachexia there is, therefore, a disso- 

 lution of lime salts, and later the tissue thus deprived of its 

 mineral substance undergoes farther ill-defined modifica- 

 tions, consisting of a transformation into a mucous sub- 

 stance. The degenerative changes are more intense in the 

 cancellated tissue, but they always reach the compact tis- 



FiG. 9S. 



Osseous Cachexia. Fragment of the Cancellated Tissue of an Osteomalactic 



Rib. (a) Normal Osseous Tissue, fb) Osseous Tissue Deprived of 



Calcareous Matter, (c) Haversian canals, (d) Medullary 



Space Filled with Red Medulla ; the Capillaries are 



Open. 



sue, which finally disappears from center to circumference. 

 This explains the enlargements of the Haversian canals and 

 the medullary canal of the long bones. The alterations form 

 cavities in bones having none with the result of diminishing 

 both the density and the weight. In view of the extensive 

 deteriorations of the osseous tissue, the chemical constitu- 

 tion of diseased bone, compared with that of normal bone, 

 is an interesting study. 



Numerous analyses, all of which vary somewhat, have 



