This formation has been too generally spoken of as pumice foot, whereas that peculiarity is altogether distinct. Pumice foot does not entirely incapacitate the horse for labor; it is a chronic disease leading to a very opposite species of distortion, or to a bulging of the sole such as is here illustrated.
A SECTION OF THE HORSE'S FOOT, ILLUSTRATING THE
DISTORTION WHICH CONSTITUTES PUMICE FOOT.
THE DEFORMITY WHICH ENSUES UPON
DROPPING OF THE COFFIN-BONE.
After dropping of the coffin-bone has taken place, it is commonly said that the hoof, struck upon the spot once occupied by the coffin-bone, emits a hollow sound; such is not the fact.
The space supposed to be empty is immediately filled by an impure horn—a soft, transparent substance, which, if the animal be permitted to live, dries, or diminishes in bulk, and the front of the hoof falls in. The author once beheld, working in a lime-pit near Reigate, an aged animal which, some time previous, had suffered dropping of the coffin-bone; the animal was shod with leather, and had a shoe lifted from the ground by means of large calkins both before and behind. The hoof, however, was terribly misshapen; it hardly admits of such a description as would be readily understood; therefore the hoof is represented from a sketch made upon the spot.
The other terminations to acute laminitis are metastasis and mortification.
Metastasis is when the fever leaves the feet to fix upon some other and remote part, as the lungs, bowels, brain, eyes, etc. Or, fever of the feet is frequently asserted to be caused by the inflammation "dropping" from those parts into the hoofs; when such changes ensue, the body being already weakened, the attack is seldom of a very acute type; but, nevertheless, it may be attended by disorganization, by distortion, or even by death.
It is a bad symptom should no change be observed in the course of the disorder before the expiration of the fifth day; some sad ending may then be expected, but it does not invariably follow. The animal should be watched night and day; all that can possibly be done to alleviate its suffering should be put into practice. For that end, the writer has found nothing equal in its soothing effects to perfect quietude, and good gruel made with a portion of linseeds and of beans mixed with oatmeal. But be sure that laminitis has departed from the feet before the slings are removed; then, even supposing no metastasis to have occurred, do not suddenly take all support from the horse, but remove a weight every day, so that the restored parts may become gradually used to their original functions. On the first sign indicative of a return to the disorder, restore the full counterpoise and recommence treatment; for acute laminitis is somewhat treacherous. Very cautiously exercise the invalid upon a piece of meadow land and, as the health appears restored, gradually return to the usual method of treatment.