Take, again, the treatment of 'unsoling.' It was barbarous, we know barbarous, because unnecessary and easily avoidable. It was practised, however, certainly very little more than two decades ago, and practised by men of standing in the profession. Without dragging the case to light again by mentioning the names of those concerned, we may mention that not many years ago a highly respected member of the profession was, at the instigation of the Royal Society for the Prevention of Cruelty to Animals, prosecuted for practising unsoling for the relief of side-bone. Practically only one other member of the profession was able to come forward and defend the operation on the score of its utility. We see now, however, that—as does Smith's operation—unsoling does permit of the greater expansion of the heels. The contraction is done away with, the pressure on the sensitive laminæ again diminished, and the lameness relieved.
Not that we are attempting to defend the operation—far from it. We simply mention it as interesting, and quote this and the use of the bar shoe (with both of which methods older operators have claimed success) merely as evidence that the operation of Smith is based on a logical foundation.
When treatment is decided on, therefore, we may first advise blistering and the use of a bar shoe. After that, should the lameness continue, and should we still judge the side-bone to be the cause of it, the operation may be advised.
As we have said before, the operation consists in so grooving the wall as to allow of the quarters widening sufficiently to relieve pressure on the parts within. In one or two previous portions of this work we have considered operations involving this procedure. Before detailing the operation here, therefore, we will first describe the instruments necessary, and the most satisfactory methods of incising the horn.
To begin with, it must be remembered that all methods of hoof section have for their object the after-expansion of the horny box, and that this can only be brought about by making each groove complete from coronary margin to solar edge of the wall, and carrying it, throughout its length, deep enough to reach the commencement of the sensitive structures.
To this end, therefore, the operator must bear in mind the comparative thickness of the various parts of the wall, and must, in particular, remember the relative thinness of that portion of horn forming the outer boundary of the cutigeral groove, and accommodating the coronary cushion.
For the making of the incisions there is the special saw devised for this operation by Colonel F. Smith, A.V.D., and which we illustrate in Fig. 144. With this the wall is sawn through until the depth arrived at is equal to what is indicated by a previous examination of the thickness of the crust as viewed from the solar surface. Here Colonel Smith says: 'I strongly advise everyone to use a metal gauge (a thin piece of material) to introduce into the incision made by the saw, and run it up and down to ascertain whether the wall is properly divided throughout. The depth to which this should be done we know from the previous measurements of our gauge on the crust.'
FIG. 144.—SMITH'S SIDE-BONE SAW (EARLY PATTERN).