FLAT SOLE. 331 



descent being greater on the side which bears the greater 

 weight. The union between the sensitive and horny structures 

 is exposed to severe strain, the laminae gradually enlarge and 

 yield, and the os pedis presses on the sensitive and horny soles 

 until it finally thrusts them downwards. This is followed by 

 changes in the sole and atrophy of the os pedis, best marked 

 at its wings and sharp plantar margin. The more developed 

 the atrophy the more convex does the horny sole appear. 

 Change in position of the os pedis, again, produces distortion of 

 the coronary band and displacement of its papilke. This gives 

 rise to the formation of rings and splits in the wall, while, 

 owing to its oblique position, the wall itself tends to bend out- 

 wards at the bearing surface. The more oblique the wall and 

 the heavier the horse the more rapidly do such changes pro- 

 ceed. When the toe is much turned out they only affect the 

 inner half of the foot, but then occur very rapidly. The flat- 

 soled hoof grows chiefly forwards and outwards, and is hence 

 very liable to suffer from separation of the wall. When the 

 heels are weak and the sole flat the heels turn inwards ; when 

 the hoof is less spread the bars may grow over the posterior 

 portions of the sole : in either case corns are common. 



It is impossible to cii^rc this flat condition of the sole. 

 Possibility of improvement exists when the condition is not 

 far advanced, when the horn fibres are fine and tough, and 

 the animal is of light weight, but, as a rule, all the unfavour- 

 able factors are combined. The animal is then absolutelv un- 

 suitable for rapid work on hard roads, and can be employed 

 only at a walk or in the fields. 



Something may be done to improve matters and prevent the 

 changes which have taken place becoming aggravated. The 

 sole, being very thin, should be trimmed as little as possible. 

 Loose fragments of horn may be removed, the bars, if over- 

 lapping the posterior portions of the sole, cut back, and the 

 bearing margin of the wall levelled with the rasp. The outer 

 edge of the wall, especially at the toe, should be well rounded 

 off, and unduly convex portions as far as possible levelled. 

 The frog and sole must be spared. Where the position of the 

 limb is normal and the horn of good quality an ordinary flat, 

 wide-webbed, well-seated shoe with a broad bearing surface, and 

 made from thick iron, is suitable ; the heels should be some- 



