4 DISEASES OF THE HORSE’S FOOT 
Leaving the forge, we may next look to the nature of the — 
animal’s work, and the conditions under which he is kept, © 
for active causes in the production of disorders of the foot. 
From the yielding softness of the pasture he is called to 
spend the bulk of his time upon the hard macadamized 
tracks of our country roads, or the still more hard and 
more dangerous asphalt pavings or granite sets of our 
towns. The former, with the bruises they will give the — 
sole and frog from loose and scattered stones, and the 
latter, with the increased concussion they will entail on 
the limb, are active factors in the troubles with which we 
are about to deal. Upon these unyielding surfaces the 
horse is called to carry slowly or rapidly, as the case may 
be, not only his own weight, but, in addition, is asked to 
labour at the hauling of heavy loads. The effects of con- 
cussion and heavy traction combined are bound primarily 
to find the feet, and such diseases as sidebones, ring- 
bones, corns, and sandcracks commence to make their 
appearance. 
Again, as opposed to the comparative healthiness of the 
surroundings when at grass, consideration must be given 
to the chemical changes the foot is frequently subjected to 
when the animal is housed. 
Only too often the bedding the animal has to stand upon 
for several hours of the twenty-four can only be fitly 
described as ‘filthy in the extreme. The ammoniacal 
exhalations from these collected body-discharges must, 
and do, have a prejudicial effect upon the nature of the 
horn, and, though slow in its progress, mischief is bound 
sooner or later to occur in the shape of a weakened and 
discharging frog, with its concomitant of contracted heels. 
Lucky it is in such a case if canker does not follow on. 
Observers, too, have chronicled the occurrence in horse’s 
feet of disease resulting from the use of moss litter. 
Tenderness in the foot is first noticeable, which tenderness 
is afterwards followed by a peculiar softening of the horn 
of the sole and the frog. What should be a dense, fairly 
resilient substance is transformed into a material affording 
