150 L.\MEXESS IN THE HORSE. 



at any time, causes lameness. Sometimes the wall bulges 

 out visibly over the cavity, especially when the latter is 

 extensive. After the shoe has been pulled off, black streaks 

 in the white line, similar to those seen in loosening of the 

 sole from the Avail, are met with. 



Palpation. — Percussion of the hoof produces a hollow 

 sound. Probing reveals the fact that the cavity extends up 

 into the sensitive structures, occasionally as far as the 

 coronet. The cavity is either empty or contains crumbly 

 disintegrated horn. The shape of the cavity is generally 

 conical, with its apex toward the coronet and its base at 

 the sole. Such a cavity rarely extends further than half-way 

 up the wall, having a width of from one-eighth to one and 

 one-quarter of an inch. 



12.— Contracted Hoof. 



All deformities of the hoof, which by their pressure upon 

 the sensitive soft parts of the hoof cause lameness, are 

 known as "contracted hoof." From a clinical standpoint it 

 is of value to subdivide them according to the various 

 regions in which the contraction may occur. Lameness is 

 more noticeable when only one hoof is involved. When 

 standing the animal points, and when both feet are con- 

 tracted the weight is frequently shifted from one leg to the 

 other. This is especially apparent when first getting up 

 after having been lying down for some time, of which the 

 animal, under these conditions, is very fond. Upright 

 fetlocks and sprung knees are often seen in the lame leg. 

 \\rhen contraction sets in gradually, lameness is occasionally 

 absent or very slight; higli strung animals frequently drive 

 out of the lameness. Lameness, the result of contraction 

 of the hoof, is in many instances periodical. 



