CONTRACTION OF THE FOOT 611 



CONTRACTION OF THE FOOT 



This reputed disease has long been the bugbeai^ of the horsemaster; 

 but it is now discovered to be a complete mistake. Some of the most 

 contracted feet in point of width are particularly free from all risk of 

 disease, and on the other hand many open ones are as liable to it. The 

 donkey, whose heels are shaped exactly like those of the contracted horse's 

 foot, is so seldom lame, that few can recall having seen one in that con- 

 dition, and, therefore, reasoning from analogy, one would be led to doubt 

 that this shape renders the horse prone to lameness. At the same time it 

 is quite true that in the disease which will next be investigated, the frog 

 withers and conti^acts, and the heels ai-e thereby drawn in ; but here the 

 contraction is a consequence and not a cause of disease, and certainly 

 cannot be considered as a disease in itself. Bad shoeing will do much to 

 cause either laminitis or navicular disease, and it will certainly produce 

 corns and inverted heels, but it will not waste the frog, or induce that 

 condition of the foot where the sole is arched so high that the frog does not 

 touch the ground when the shoe is off. Such a state of things can only be 

 brought on either by thrush or navicular disease, and is never the result of 

 the mechanical mismanagement of the foot, to which what used to be called 

 contraction was generally attributed. All sorts of plans have been sug- 

 gested for expanding the heels and for allowing them to expand ; but the 

 real truth is that so long as the frog is sound and the parts above it, allowing 

 the proper amount of pressure to be communicated to the sole, bars, and 

 heel of the crust, these latter divisions of the foot have no room to contract, 

 and of a certainty they never do. • 



NAVICULAR DISEASE 



This formidable disease, called also the navicular joint lameness, and 

 navicularthritis, is the chief danger to be aj^prehended from a good-looking 

 strong foot, just as the open flat one is prone to laminitis, and is rarely 

 subject to disease in the navicular joint. The reason of this immunity on 

 the one hand, and the contrary on the other, is this. The open foot, with 

 a large spongy frog, exposes the navicular bone and the parts in contact 

 with it to constant pressure in the stable, so that these parts ai'e always 

 prepared for work. On the other hand, the concave sole and well-formed 

 frog are raised from the ground by our unfortunate mode of shoeing, and 

 when the whole foot is exposed to injury from battering, and in addition 

 the tendon which plays over the navicular bone presses it against the os 

 coronre, the unprepared state in which this part is allowed to remain is sure 

 to produce inflammation, if the woi-k is carried far enough. Thus in each 

 case the weak part suffers, but occasionally, though very rarely, the foot 

 with an arched sole contracts laminitis, and the flat one is attacked by 

 navicular disease ; the exceptions, however, are so few that they may be 

 thrown out of the calculation, and from the shape of the foot alone it may 

 almost invariably be pronounced, when a horse is known to be subject to 

 chronic lameness, whether its seat is in the laminre or in the navicular joint. 



