.370 A Manual of Veterinary Physiology. 



Such are the physiological features of the foot which 

 facilitate circulation and. destroy concussion. Foot-lame- 

 ness is only too frequent, but if it were not for the 

 mechanism we have described, it would not be possible 

 for us to work horses for a single day. It is no argument 

 against expansion that it requires delicate apparatus to 

 detect it, owing to its minuteness ; small as it is in the 

 slower paces, it yet suffices to convert what would be a 

 rigid, unyielding block into an elastic and yielding one ; and 

 at the gallop the expansion must be considerable, probably 

 more than double what it is under ordinary conditions. 



Physiological Shoeing. — It is impossible to conclude this 

 chapter on the foot without some mention of what we 

 might term physiological shoeing. 



We all recognise the evil of shoeing as strongly as we 

 recognise its necessity. By bearing in mind the functions 

 of the various parts of the foot, we can certainly reduce the 

 evil of shoeing to comparatively narrow limits, and in a few 

 words we will state what constitutes physiological shoeing : 



1. The reduction of the wall to its proper proportions, 

 such as would have occurred through friction had no shoe 

 been worn. 



2. Fitting the shoe accurately to the outline of the foot, 

 not altering the latter to lit the shoe. Rasping away the 

 crust to fit the shoe not only renders the horn brittle, but 

 is so much loss of bearing surface. 



3. Leaving the wall intact, so far as its varnish -like 

 layer is concerned. The practice of rasping the wall for 

 appearance' sake destroys the horn tubes, and allows of so 

 much evaporation from the surface of the foot that the 

 wall becomes brittle. 



4. The sole not to be touched by the knife ; it cannot be 

 too thick ; it is there for the purpose of protection. 



.*>. The bars not to be cut away ; they are part of the 

 wall, and intended to carry weight. The shoe should rest 

 <>n them. 



(i. The frog to be uncut and left to attain its full growth, 

 which can only occur through resting on the ground. No 



