324 DISEASES OF THE HOESE. 



dents happening hourly by which our equine servants become suffer- 

 ers. We may add to these the fracture of the bones of the vertebrae, 

 occurring when casting a patient for the purpose of undergoing a 

 surgical operation, quite as much as the result of muscular contrac- 

 tion as of a preexisting diseased condition of the bones. A fracture 

 occurring under these circumstances may be called with propriety 

 indirect, while one which has resulted from a blow or a fall differ- 

 ently caused is of the direct kind. 



SymptoTifhs. — ^We now relurn to the first items in our clas'sification 

 of the varieties of fractures for the purpose of bringing them in turn 

 under an orderly review, and our first examination will include those 

 which belong to the first category, or the complete kind. Irregu- 

 larity in the performance of the functions of the apparatus to which 

 the fractured bone belongs is a necessary consequence of the existing 

 lesion, and this is lameness. If the broken bone belongs to one of the 

 extremities, the impossibility of the performance of its natural func- 

 tion in sustaining the weight of the body and contributing to the act 

 of locomotion is usually complete, though the degree of disability 

 will vary according to the kind of fracture and the bone which is 

 injured. For example, a fracture of the cannon bone without dis- 

 placement, or of one of the phalanges, which are surrounded and sus- 

 tained by a complex fibrous structure, is, in a certain degree, not 

 incompatible with some amount of resting on the foot. On the con- 

 trary, if the shank bone, or that of the forearm is the implicated 

 member, it would be very difficult for the leg to exercise any agency 

 whatever in the support of the body, and in a fracture of the lower 

 jaw it would be obviously unreasonable to expect it to contribute 

 materially to the mastication of feed. 



It seldom happens that a fracture is not accompanied with a de- 

 gree of deformity, greater or less, of the region or the leg affected. 

 This is due to the exudation of the blood into the meshes of the 

 surrounding tissues and to the displacement which occurs between 

 the fragments of the bones, with subsequently the swelling which 

 follows the inflammation of the surrounding tissues. The character 

 of the deformity will mainly depend upon the manner in which the 

 displacement occurs. 



In a normal state of things the legs perform their movements with 

 the joints as their only centers or bases of action, with no participa- 

 tion of intermediate points, while with a fracture the flexibility and 

 motion which will be observed at unnatural points are among the 

 most strongly characteristic signs of the lesion. No one need be 

 told that, when the shaft of a limb is seen to bend midway between 

 the joints, with the lower portion swinging freely, the leg is broken. 

 There are still some conditions, however, in which the excessive 

 mobility is not easy to detect. Such are the cases in which the frac- 



