838 DISEASES OF THE HORSE, 
syringe, the milk or nutritive gruels selected for his sustenance until 
the consolidation is sufficiently advanced to permit the ingestion of 
feed of a more solid consistency. The callus will usually be suffi- 
ciently hardened in two or three weeks to allow of a change of diet 
to mashes of cut hay and scalded grain, until the removal of the 
dressing restores the animal to its old habit of mastication. 
FRACTURES OF VERTEBR2. 
These are not very common, but when they do occur the bones most 
frequently injured are those of the back and loins. 
Causes.—The ordinary causes ot fracture are responsible here as 
elsewhere, such as heavy blows on the spinal column, severe falls 
while conveying heavy loads, and especially violent efforts in resist- 
ing the process of casting. Although occurring more or less 
frequently under the latter circumstances, the accident is not always 
attributable to carelessness or error in the management. It may, of 
course, sometimes result from such a cause as a badly prepared bed, 
or the accidental presence of a hard body concealed in the straw, or 
to a heavy fall when the movements of the patient have not been 
sufficiently controlled by an effective apparatus and its skillful 
adaptation, but it is quite as liable to be caused by the violent 
resistance and the consequent powerful muscular contraction by the 
frightened patient. The simple fact of the overarching of the 
vertebral column, with excessive pressure against it from the in- 
testinal mass, owing to the spasmodic action of the abdominal 
muscles, may account for it, and so also may the struggles of the 
animal to escape from the restraint of the hobbles while frantic 
under the pain of an operation without anesthesia. In these cases 
the fracture usually occurs in the body or the annular part, or both, 
of the posterior dorsal or the anterior lumbar vertebra. When the 
transverse processes of the last-named bones are injured, it is probably 
in consequence of the heavy concussion incident to striking the 
ground when cast. The diagnosis of a fracture of the body of a 
vertebra is not always easy, especially when quite recent, and more 
especially when there is no accompanying displacement. 
Symptoms.—tThere are certain peculiar signs accompanying the 
occurrence of the accident while an operation is in progress which 
should at once excite the suspicion of the surgeon. In the midst of 
a violent struggle the patient becomes suddenly quiet; the movement 
of a sharp instrument, which at first excited his resistance, fails to 
give rise to any further evidence of sensation; perhaps a general 
trembling, lasting for a few minutes, will follow, succeeded by a cold, 
profuse perspiration, particularly between the hind legs, and fre- 
quently there will be micturition and defecation. Careful examina- 
tion of the vertebral column may then detect a slight depression or 
