Page:The American Cyclopædia (1879) Volume XVI.djvu/354

 VETERINARY SCIENCE vated by the tension of the fibrous membrane over a rapidly growing swelling, and in spavin by the increased strain thrown on a sinew which passes over the seat of enlargement ; in such cases a skilful division of these structures with a narrow-bladed knife, which will make little more than a puncture in the skin, is fol- lowed by the best results. Ringbone*, which appear as hard swellings on the bones between the fetlock and hoof, generally take their ori- gin at points where the lateral ligaments of the joints are attached, though they may arise from concussion and injury to the front as well. In these, as in splints and spavins, the inflamma- tion may subside, the exudate harden into bone, and all lameness disappear, so that the swell- ing remains only as an eyesore and not a real injury. But from the constant strain on the lateral ligaments, when standing aa well as at work, the inflammation is far more likely to be kept up, and the enlargement to go on in- creasing, making ringbones more dangerous than splints or spavins. Again, if they extend over the joints, as they often do, they give rise to a permanent stiffness and lameness, by abol- ishing the considerable movements normally effected in these. The treatment of ringbones is therefore far less satisfactory than that of splints and spavins. It proceeds on the same principle, first by soothing and antiphlogistic applications when inflammation is acute, and later by blistering or firing when its severity is somewhat moderated. The counter irrita- tion must usually be more severe and repeated than in the other affections, and deep firing in points must often be resorted to. Any of the above named forms of bone disease may be primarily dependent on a constitutional infirm- ity with impaired nutrition of the skeleton, and in such cases an improvement of digestion and general tone must first be secured. Such general infirmity is usually betrayed by the co- existence of several such causes of unsoundness in the same animal (splints, spavins, ringbones, navicular disease, sprains, &c.), by the passage of an excess of earthy salts (phosphates) in the urine, and by a general lack of energy and endurance. IV. SHOEING AND DISEASES OF THE FEET. A great majority of diseases of the feet take their origin in faulty modes of shoo- ing. The hoof is made up of horny tubules, all excepting some of those of the frog running from above downward and forward. Near the quick these are wide and open, filled with liquid, and surrounded by a soft, moist, horny substance ; but in approaching the surface they become finer, closer, and encircled by horn of almost flinty hardness. The tubes of the hoof wall extend from the coronet to the lower wearing border, where they are closed by at- trition. Those of the sole are covered by thick horny scales or flakes, with a fine powder be- tween them and the tough elastic horn, and effectually protecting the latter from desicca- tion and mechanical injury. In the healthy state therefore the whole hoof is well provided against evaporation, drying, and shrinking. But the case is altered when the tubes of the hoof wall are laid open with the rasp, and those of the sole and frog with knife and buttress. Then the moisture is ram'dly exhaled, the horn dries and shrinks, the heels curl inward, and the sole becomes more arched, drawing in the lower border of the hoof wall. The sensitive parts beneath are absorbed under the pressure, and distortion and weakness are inevitable re- sults, even if active disease is for a time escaped. A free use of hoof ointments will to some ex- tent obviate the evil, though they make but a poor substitute for nature's admirable protec- tion. The preservation and preparation of the foot is of far more consequence than the form of shoe. The hoof should be interfered with as little as possible, save where the shoe is to rest. This part should bo pared or rasped until the elastic horn is reached, and so as to leave a smooth bearing surface, extending on the sole to a distance of perhaps half the thick- ness of the hoof wall. The two sides, inner and outer, should be of uniform height at all corresponding points, and the heel and toe left of an elevation according with the natural form of the particular foot. Usually the cutting must be almost entirely confined to the toe. While avoiding the paring of the tough elastic horn of the heel, we must equally avoid leaving hard thick flakes of dead horn, which can only act as foreign bodies and bruise the part. The outer edge of the hoof wall may be slightly rounded with a file, to obviate splitting. The foot having thus been prepared with corre- sponding height on both sides, and in a way to prevent any distortion of the bones and joints of the limb from their natural direction, tho next point is to adapt the shoe to the wearing surface. Tho upper surface of the shoe should bo perfectly level, unless a very gentle curve is given from heel to toe, and the bearing on the hoof should be uniform throughout, as unequal pressure will tell sooner or later on the foot, or on the bones and joints above. Fitting the shoe at a dull red heat is hurtful to the horn, but of two evils it is preferable to unequal bearing. For perfect fit it is better to have the shoe coarsely fullered, and to drive the nails rather low as tending to injure less horn, and the hold taken should be gradually less in approaching the heel, especially on the inner side. The nails should be drawn up so as to hold the shoe firm, but no more; and in riveting, the transverse groove usually made with the rasp should be avoided, though a slight notch may be made with the knife beneath each nail, to receive the clench. In filing off any roughness of the clinches, avoid touching the hoof. Finally, remove tho shoe before the hoof grows over it, and especially before the growth of the toe has drawn it for- ward so that it sets in on the heels. Naticular Disease. This is a disease of a small bone situ- ated beneath the coffin joint, and serving as a pulley over which plays the flexor tendon of