[Illustration:  FIG. 110.—­UNDER SURFACE OF THE TOE OF A HIND-SHOE. a, Marks the portion of the inner margin that inflicts overreach.]

[Illustration:  FIG. 111.—­THE INNER MARGIN OF THE INFERIOR SURFACE OF THE HIND-SHOE BEVELLED TO PREVENT OVERREACH.]

Curative.—­Although in some cases it is so small as to go undetected, we may take it that in all cases of coronitis there is a wound, with consequent danger of septic infection of the surrounding parts.  Therefore, after attention to the shoeing and removal of the cause, the first indication in the treatment will be to render the parts aseptic.  This is best done by removing the hair from the coronet and soaking the whole foot in a cold antiseptic solution.  After removal from the bath, the coronet may be dressed with a moderately strong solution of carbolic acid or perchloride of mercury.  When the injury is slight and recent, such is sufficient to effect resolution.

When marked swelling persists, however, and the increase in heat and tenderness denotes the formation of pus, recovery is not so easily obtained.  In this case the application of hot poultices or hot baths is called for.  By these means suppuration is promoted and induced to early break through in the most favourable position—­namely, the softened skin of the coronet.  The pus so escaping is always more or less blood-stained, and contains both large and small pieces of broken down and decomposed tissue.  After discharge of the pus, the cavity remaining should be mopped out with an antiseptic solution, and a pledget of antiseptic tow or other material left in position.  All that is then needed is constant dressing in a suitable manner.  We prefer in this instance washing some three or four times a day with hot water until a perfectly clean wound is obtained, and, after the washing, painting the raw surface with a strong solution (1 in 200, or 1 in 100) of perchloride of mercury.

When the abscess we have described as forming is extremely large, or where it is more than ordinarily slow in ‘pointing,’ the likelihood of its having burrowed for some distance below the upper margin of the wall must be suspected.  Here it is sometimes wise to thin the wall with the rasp immediately below the point of greatest swelling of the coronet.  This will serve to lessen pressure on the sensitive structures beneath.

Immediately the abscess contents have found exit at the coronet, the cavity formerly occupied by the pus should be explored.  If to any extent it is found then to have ‘pocketed’ beneath the upper border of the wall, a counter-opening should be made where the horn of the wall has been thinned with the rasp.