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that the bones of the true hock joint do become implicated, as the disease 

 spreads ; but it is not by any means a common occurrence. One will 

 readily understand that the higher the bony growth is deposited, the more 

 grave are the consequences. On the other hand, when seated lower down 

 between the canon bone and the little bone immediately above it, the 

 cementing together of the joint is not of great moment. The progression of 

 the animal in this case is not much affected thereby, as there is but little 

 motion in this joint. The causes of spavin are of two kinds, actual or 

 external, and predisposing or internal. 



There are a number of predisposing causes, which we may briefly 

 consider. Firstly, the bones of young and overgrown horses being soft and 

 immature, are more liable to become diseased. One can readily understand 

 that, at an early age, the bones and their coverings, as well as the joints and 

 ligaments, are most liable to beconxe diseased, especially when the animal 

 is heavily weighted, before his bony tissues are really consolidated. Secondly, 

 irregular conformation of the hock joint is also to be regarded as a 

 predisposing factor in the causation of spavin. When the angle of the hock 

 is less than 135°, the animal is termed " sickle-hocked." Such a conformation 

 of hock we mentioned was unsuited for rapid progression, and is especially 

 liable to curb. Likewise it is believed to be more liable to become the seat 

 of spavin, though the predisposition to this disease is not so marked, as in 

 the case of curb. Wide hocks, sometimes caused by bad shoeing, or disease 

 of the fetlock joint ; straight hocks, in which the angle of the joint is more 

 than 160^; and cow hocks are also examples of irregular construction of 

 these parts. We do not know that these latter irregularities increase the 

 liability to spavin. Animals with " laced-in hocks " or " tied in below the 

 hock" are also especially subject to spavin ; and this is also the case in 

 animals with short or round hocks. Thirdly, excitable animals of irritable 

 temperament, it is believed, are also more subject to contract spavin. Fourthly, 

 animals with long backs and narrow hind quarters, are more prone to the 

 osseous disease of the hock in question. Lastly, hereditary predisposition is 

 veiy marked in this inflammatory disease. 



The actual causes of spavin are strain or concussion of the structures 

 of the joint, due to galloping, or veiy hard work, or wearing shoes with toa 

 high calkins, and imperfect food supply. Necessarily, if the food is 

 insufficient and of bad quality, the animal will be more subject to spavin, 

 and, indeed, also to sprains of the various muscles and tendons of the body. 

 It is in cart-horses that high calkins not uncommonly are answerable for the 

 production of spavins ; and this is especially the case, when the animal is 

 employed for drawing heavy weights down hill. It is necessary that animals 

 employed for hunting should have well formed hocks, because the amount of 

 concussion on the hocks in leaping renders them more liable to suffer from 

 spavin, and one rarely sees an animal which has been hunted for a couple of 

 seasons without observing that he has thrown out spavins. It is not strange 

 that the more forward the spavin appears, the greater is the resulting 

 impediment to the progression. 

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