bones: diseases and accidents. 271 



wise so as to twist the back, or from slipping violently backward so 

 that great stress is thrown on the loins. The patient moves with 

 difficulty, using the hind parts in a guarded manner, as if afraid of 

 causing severe pain. Occasionally, if the sprain is severe, the animal 

 will rise with difficulty. Pressure on the back in the immediate region 

 of the loins causes pain. Such cases may be mistaken for paralysis, 

 and, in fact, in severe cases, during the early stages of the injury, 

 although the nerve supply is not interfered with, the injury to the 

 muscles and resulting pain is so great that the condition is almost 

 equal to paral5^sis, although liable to be attended with more favorable 

 results. Hot applications, such as blankets wrung out of hot water 

 and changed often, will be likely to afford relief during the earlier 

 stages. Afterwards the blister mentioned for sprain of the shoulder 

 may be applied with advantage. 



FRACTURES (BROKEN BONES). 



Bones may be accidentally broken in manj^ ways and from differ- 

 ent causes. Fractures in general are liable 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 re- 

 mote 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, owing to their exposed position, are more liable 

 to fracture than others. Owing to certain predisposing causes, such 

 as age, habit, or hereditary constitutional weakness, the bones of 

 some animals are more easily fractured than thore of others. 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 liable 

 to occur in a young animal in which the preponderance of animal 

 matter or the semicartilaginous 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 bends and breaks. 



Simple eractubes. — Simple fracture is one in which the bone is 

 severed in two parts, transversely, longitudinally, or obliquely, with- 

 out serious injury to the adjoining structures. 



Compound fractures, — Compound fracture is one in which there 

 is an open wound permitting the air to communicate with the ends 

 of the broken bones. 



