172 THE PRACTICE OF VETERINARY MEDICINE. 



Symptoms. — After necrosis takes place material is exuded 

 by which the necrosed bone becomes covered to a certain 

 extent, soon swelling becomes apparent ; after a while there 

 is a discharge from the affected part and an abscess is 

 formed, at which time the dead bone is separating from the 

 living, and is enclosed within an exudate. 



Treatment. — Enlarge the opening from which the dis- 

 charge is flowing, and with the fingers or forceps remove 

 the dead portion of bone. 



Necrosis also occurs in connection with other parts besides 

 the one mentioned, as the point of the ilium sometimes 

 becomes necrosed in consequence of an injury. The symptoms 

 and treatment are the sanie as above described. 



When external exfoliation takes place in one of the 

 cylindrical bones, the process is very tedious, and more so 

 than in any other bone, as when necrosis is going on an 

 exudate is thrown out between the necrosed bone and the 

 adjoining bone, giving rise to an inflammatory process, 

 swelling and suppuration ; the covering by the exudate is 

 not complete, but there are small openings through which 

 matter is discharged ; it might be said that the bone is dead, 

 and ' buried ' in new bone. It affects the constitution to 

 such an extent that generally it pays best to destroy the 

 patient unless valuable. A new bone may be formed 

 which will exhibit nearly the same characteristics as the 

 original bone. 



Abscess of Bone. — Abscess of bone is also a result of 

 ostitis, but is of very rare occurrence. In some cases pus may 

 be confined within the bone for an indefinite period ; in- 

 flammation is first set up in the cancellated tissue of the 

 bone, its exciting cause being usually a blow or kick, and 

 instead of the formation of ossific material, pus is formed, 

 and an abscess results. 



Symptoms. — After the formation of pus takes place, a con- 



