DISEASES OF CATTLE 439 



FRACTURES (BROKEN BONES ). 



Bones may be accidentally broken in many ways and from dif- 

 ferent causes. Fractures in general are likely to be produced by ex- 

 ternal force suddenly and violently applied, either directly to the 

 part or at a distance, the force being transmitted through the stronger 

 bones until it expends itself by breaking a weaker one remote from 

 the seat of the injury. Occasionally violent contraction of muscles 

 is sufficient to break a bone. Certain bones, those of the limbs in 

 particular, are more liable to fracture than others, owing to their ex- 

 posed position. The bones of some animals are more easily fractured 

 than those of others, owing to certain predisposing causes, such as 

 age, habit, or hereditary constitutional weakness. The bones of an 

 animal advanced in years are more subject to fracture because of the 

 preponderance of inorganic matter rendering them more brittle. 

 They are also occasionally rendered liable to fracture by a previously 

 existing diseased condition. Fractures are divided into four classes 

 partial, simple, compound, and comminuted. 



PARTIAL FRACTURES. 



Partial fractures are those which are likely to occur in a young 

 animal in which the preponderance of animal matter or the semicar- 

 tilaginous condition of the bone renders it tough, so that even when 

 considerable force is applied the bone bends, breaking on the side 

 opposite that to which the force was applied, after the manner in 

 which a green stick would bend and break. 



SIMPLE FRACTURES. 



Simple fracture is one in which the bone is severed in two parts, 

 either transversely, longitudinally, or obliquely, without serious in- 

 jury to the adjoining structures. 



COMPOUND FRACTURES. 



Compound fracture is one in which there is an open wound per- 

 mitting the air to communicate with the ends of the broken bones. 



COMMINUTED FRACTURES. 



Comminuted fracture is one in which the bone is shattered or 

 divided into a number of fragments. 



COMPLICATED FRACTURES. 



Complicated fracture is one where other structures surrounding 

 the bones are injured. 



GENERAL SYMPTOMS OF FRACTURE. 



When a fracture of one or more of the large bones of a limb 

 occurs, symptoms are sure to be well marked. After the accident the 

 animal refuses to touch the foot to the ground and, if compelled to 

 move, does so with great pain and reluctance. There is more or less 

 shortening of the limb, with trembling of the muscles in the vicinity 

 of the injury ; deformity, and increased mobility, so that, instead of 

 the natural joints of the limb and the natural muscular control of 

 their motion, a new joint is formed where the fracture occurred, over 

 which the animal has no control. As the leg hangs dependent from 

 the body, shortened by the ends of the bones being forced past one 

 another from the muscular contraction which invariably takes place, 

 it swings in an awkward and unnatural manner, permitting the toe 



