CONTRACTION AT CORONARY MARGIN OF HOOF. 359 



later. Eest in the stable will produce similar results. The 

 causes are shoeing, deiicient frog support, desiccation, and 

 insufficient exercise. 



The prognosis is favourable and lameness disappears when 

 the contraction has grown down as far as the lower third of 

 the wall. When it affects only the posterior part of the heel 

 it can be removed in two or three shoeings, but if the feet are 

 flat and the contraction extends further forward it may persist 

 for a much longer time. Treatment consists in paring the 

 hoof, so as to produce a level tread and straight foot axis ; 

 the use of shoes of a thickness proportioned to the animal's size 

 a,nd work, and such as will allow the frog to bear weight. 

 The bearing surface of the shoe should be horizontal at the 

 heels : the other portions may be horizontal or inclined slightly 

 inwards, depending on whether the sole is concave, flat, or con- 

 vex. If the frog is well developed and projects below the wall 

 an ordinary thin-heeled shoe is most suitable, as it allows the 

 frog to touch the ground. If, however, the frog is low or 

 badly developed, a bar shoe is preferable. With this the neces- 

 sary frog pressure can generally be produced, even when the 

 frog is affected with thrush. In such case the frog is cleansed 

 and disinfected, well smeared with tar or Venice turpentine, 

 and the bar shoe, provided with a leather sole and plenty of 

 stopping, nailed on. Needless to say any, portions of the wall 

 which appear painful must be eased, that is, where it is 

 impracticable to sufficiently seat out the shoe, a sHght amount 

 must be removed from the bearing surface directly below, before 

 affixing the shoe. 



In cases of even well-marked lameness thinning of the heel 

 wall and four to eight days continued poulticing is often 

 sufficient. The hoof should be kept moist and the animal 

 exercised at a walk. 



This treatment is not directed towards preventing contraction 

 at the bearing surface, but only aims at restoring the natural 

 counter-pressure of the ground and thus promoting expansion of 

 the hoof. Other means of relieving the heels and forcing the 

 frog to bear a certain amount of weight, like the use of tips, 

 filling the hoof with elastic cement, etc., are sometimes found 

 advantageous. So far as its occurrence, position, and treatuicnt 

 are concerned, contraction of the coronary margin may be 



