90 FRACTURES AND DISEASES OF BONES. 



most common of these, in the lower animals, is the inahility 

 to prevent motion in the limb. Temperament has much to 

 do with this. A calm, good-tempered horse may make a 

 good recovery, whilst an irritable, fretful animal will keep an 

 injured limb in a state of continual motion, will take un- 

 kindly to the slings, and thus render union an impossibility. 

 In addition to or independently of this want of repose, even 

 in a simple fracture, a piece of muscle or other soft tissue 

 may be imprisoned between the broken ends of the bones, 

 and if this is not removed, union is not likely to take 

 place. When a fracture is oblique, this complication is not 

 at all uncommon. 



When a fracture is comminuted, and a large portion of bone 

 denuded of its periosteum, it can be easily seen why union does 

 not take place. Necrosis of the fragments will be almost sure 

 to occur, leading on to suppuration, loss of substance, and the 

 exhaustion of the patient. 



Again, if the violence causing the fracture be very great in- 

 deed, the vitality of the surrounding textures may be destroyed, 

 or the non-union may proceed from impaired vitality of the 

 bone itself; and this may arise from the nutritious artery of the 

 bone being implicated. In such a case, union of the deep-seated 

 parts of the fracture would be very improbable. 



Surrounding circumstances and food have an effect upon the 

 repair of fractures. Where stables are overcrowded and ill 

 ventilated, necrosis and suppuration will most likely occur ; and 

 if these be associated with improper food, it will be useless for 

 the practitioner to undertake the treatment. 



I have seen cases where union of the pelvis did not com- 

 mence until the food had been changed. If it be possible to 

 give green food, it should always have a preference over all 

 other; failing this, carrots, potatoes, or turnips should be allowed, 

 in addition to hay and corn. 



The constitutional causes of non-union are those of a de- 

 bilitating nature, arising from old age, hard usage, or disease. 

 If a great number of horses are stabled togetlier, no matter how 

 good the ventilation, drainage, food, &c., may be, a peculiar taint 

 is often produced upon their constitutions by an animal malaria, 

 causing a cachexia, or condition of body in which the reparative 

 powers are in a depressed and languid condition; in such the 

 repair of fractures is effected with diriiculty. 



