386 INFLAMMATION OF STRUCTURES ENCLOSED BY THE HOOF. 



3. TkEADS ON THE CORONET 



are often produced, in horses with itchy legs, by the animal 

 rubbing the coronet with the heel of the opposite shoe. At 

 intervals the horse stamps violently, and it is then that the 

 injury is done. The front and inner side of the coronet of 

 hind-feet are most frequently injured. A ' tread ' is a bruise 

 or contused wound, associated with inflammation of the coronary 

 band, which often results in destruction of a portion of the 

 horn-secreting structures and permanent injury to the hoof. 

 Such accidents are commonest in winter when animals are 

 shod with sharp heels. 



The inflammation results either in resolution or in necrosis 

 with suppuration. The periople when separated does not again 

 become adherent, • and in consequence of this and of the 

 interrupted formation of horn a cavity results in the horn wall 

 (see page 372). When lameness follows treads, the portion of 

 the wall below the injury must be relieved of weight. In fresh 

 cases the injured parts should be carefully cleansed with warm 

 water, all dirt, hairs, and loose portions of tissue removed, and 

 some antiseptic (5 per cent, carbolic lotion) or mild astringent, 

 like 5 per cent, alum or acetate of lead solution, applied. 

 Severe treads always require the attention of a veterinary 



surgeon. 



4. Inflammation of the Perioplic King. 



The periopUc ring becomes inflamed comparatively seldom. 

 The inflammation may affect the entire ring or, as when it 

 results from dirt and irritants, only the portions above the 

 toe wall. 



The S7/mptoms are increased warmth, swelling, tenderness 

 on pressure, in white feet well-marked redness of the skin, 

 and (later) a change in the condition of the perioplic ring and 

 superficial sheath of the hoof. This superficial sheath exhibits 

 elevations and depressions, running parallel with the coronet, 

 and thus forming more or less complete rings, or the perioplic 

 ring becomes irregularly thickened. The perioplic horn after- 

 wards cracks longitudinally and transversely, giving the affected 

 part of the hoof an appearance resembling the bark of an elm 



