It has been previously remarked that an element of danger necessarily enters into the act of casting horses and retaining them in a fixed position on the ground. The risk is comparatively small in connection with colts, whose tissues are elastic; but injuries arising from this cause having from time to time occurred to animals of great value, an exaggerated importance has been attached to it, hence the standing operation, which in recent years has been largely adopted, both by veterinary surgeons and the ordinary castrator.
The usual plan of the standing operator is to have the subject placed against a padded wall or partition in which a strong ring staple is fixed, and a running noose through it is passed over the animal's withers, whereby it is possible to keep him from turning round. A twitch is placed upon the upper lip in the usual way, and then by dint of threats and feints and the pain of the twitch together, the colt is induced to remain upon his feet. Many colts can be induced to stand with no other restraint than the twitch, as the fact of having the testes firmly held prevents them from kicking or striking. One effect of the pain they suffer is to make them crouch in a manner inconvenient to the operator. To keep them on their feet is the chief difficulty, and despite the twitch, shouts, and gestures of those who adopt this method, some will lie down. Taking advantage of the upright position the castrator grasps the scrotum in the left hand, and with a clean stroke of the knife liberates first one testicle and then the other. The testicles being liberated from the scrotum, there remains a choice of methods as to their removal. Some apply the caustic clamp, the central groove of which is charged with a paste of perchloride of mercury and whiting, or some other destructive agent, which, together with the compression of the cord, corrode and strangulate the tissues. When this has been effected the clamps are removed. A quicker way of performing the standing operation is by severing the cord at once with a double-toothed instrument (fig. 522), which compresses and divides it at the same time, no clamp or other means of arresting haemorrhage being adopted. Another instrument, known as the ecraseur (fig. 523), and first introduced into this country by a famous American castrator, is in the nature of a chain, and performs its task in a similar manner to the crushing serrated instrument last referred to. The advocates of the standing operation not only claim to avoid those accidents which result from casting, but likewise to ensure greater cleanliness and less liability to infection of the wounds while the horse is upon the ground.
Fig. 522. - "Reliance" Castrator.
PLATE LVI. CASTRATION.
A. By uncovered testicle. B. By limited torsion.