The only remedy is by operation; make an incision so as to embrace the greatest number of holes. Then cut from the other openings into the main channel; this done, have the sides of the wound held back, while the center of corruption is cleaned out. Such is a very filthy and unpleasant office; if the bones are affected, all the diseased parts must be removed. When slight, the tainted portions may be scraped away; when of long standing, the spines of the vertebræ have been sundered with the saw and thus taken from the body. At any risk, none but healthy bone must be suffered to remain; all discolored or white portions of the bony structure must be extirpated, and none but that which, is of a healthy pink color suffered to continue. If a particle of unhealthy, osseous growth is left behind, the wound may close, but it will break out again, and the disease become as bad as ever.
A HORSE WITH FISTULOUS WITHERS IN THE WORST STAGE.
The cleansing being accomplished, apply the cloth over the wound, and keep wet with the lotion formerly directed to be used.
Sometimes the sinuses will take a dangerous direction, and, favored by the action of the shoulder, will burrow from the withers to the chest or elbow. Then the knife cannot be employed. Should a pipe incline to this course, but be of comparatively short extent, insert a little bichloride of mercury down the channel. This is best done by powdering some of the salt. Dip the elastic probe, which has recently been down the sinus, into the powder. Reinsert it, and continue to repeat this action till all the bichloride is expended.
If the sinus should have run its entire course, but not have found an exit below, then employ a long guarded seton needle, such as can be purchased at all veterinary instrument makers. Insert this in its guarded state, and, having pushed it as far as it will go, give, upon the end of the handle, a moderately sharp blow; this will force out the cutting edge and drive the point through the flesh. Pass a long tape, with a knot at the further end of it, through the opening near the point, and withdraw the instrument, leaving the tape in after another knot has been tied at the other extremity.
Thus a seton is established, and a depending orifice is instituted. The tape will act as a drain to the morbid secretion, while the irritation produced by it will also remove the callous lining of the pipe. A healthy action will thereby be established; and so soon as the inferior wound discharges a full stream of thick, creamy pus, the seton may be cut out, with a conviction that its office is fulfilled.
A GUARDED SETON NEEDLE.