Special Report on Diseases of the Horse
Chapter 71
The horse should next be observed at a walk and at a trot or pace, from in front, from behind, and from the side, and the "breaking over," the carriage of the feet, and the manner of setting them to the ground carefully noted and remembered. A horse does not always move just as his standing position would seem to imply. Often there is so great a difference in the form and slant of two fore hoofs or two hind hoofs that we are in doubt as to their normal shape, when a few steps at a trot will usually solve the problem instantly by showing us the line of flight of the hoofs and referring them to the regular, base-wide, or base-narrow form.
No man is competent either to shoe a horse or to direct the work till he has made the precited observations.
PREPARATION OF THE HOOF FOR THE SHOE.
After raising the clinches of the nails with a rather dull clinch cutter ("buffer") and drawing the nails one at a time, the old shoe is critically examined and laid aside. Remaining stubs of nails are then drawn or punched out and the hoof freed of dirt and partially detached horn. The farrier has now to "dress" the overgrown hoof to receive the new shoe; in other words, he has to form a base of support so inclined to the direction of the pasterns that in motion this surface shall be set flat upon the ground. He must not rob the hoof nor leave too much horn; either mistake may lead to injury. If he has made a careful preliminary examination he knows what part of the wall requires removal and what part must be left, for he already knows the direction of the foot axis and the wear of the old shoe and has made up his mind just where and how much horn must be removed to leave the hoof of proper length and the foot axis straight.
A greatly overgrown hoof may be quickly shortened with sharp nippers and the sole freed of semidetached flakes of horn. The concave sole of a thick-walled, strong hoof may be pared out around the point of the frog, but not so much as to remove all evidences of exfoliation. The wall should be leveled with the rasp till its full thickness, the white line, and an eighth of an inch of the margin of the sole are in one horizontal plane, called the "bearing surface of the hoof." The bars, if long, may be shortened, but _never pared on the side_. The branches of the sole in the angle between the bars and the wall of the quarters should be left a little lower than the wall, so as not to be pressed upon by the inner web of the shoe. "Corns," or bruises of the pododerm, are usually a result of leaving a thick mass of dry, unyielding horn at this point. The frog should not be touched further than to remove tags or layers that are so loose as to form no protection. A soft frog will shorten itself spontaneously by the exfoliation of superficial layers of horn, while if the frog is dry, hard, and too prominent it is better to soften it by applying moisture in some form, and to allow it to wear away naturally than to pare it down. It is of advantage to have the frog project below the level of the wall an amount equal to the thickness of a plain shoe, though we rarely see frogs of such size except in draft horses. The sharp lower border of the wall should be rounded with the rasp to prevent its being bent outward and broken away. Finally, the foot is set to the ground and again observed from all sides to make sure, that the lines bounding the hoof correspond with the direction of the long pastern.
THE SHOE.
The shoe is an artificial base of support, by no means ideal, because it interferes to a greater or less degree with the physiology of the foot, but indispensable except for horses at slow work on soft ground. Since a proper surface of support is of the greatest importance in preserving the health of the feet and legs, it is necessary to consider the various forms of shoes best adapted to the different forms of hoofs. Certain properties are common to all shoes and may be considered first. They are form, width, thickness, length, surfaces, borders, "fullering," nail holes, and clips.
_Form._--Every shoe should have the form of the hoof for which it is intended, provided the hoof retains its proper shape; but for every hoof that has undergone change of form we must endeavor to give the shoe that form which the hoof originally possessed. Front shoes and hind shoes, rights and lefts, should be distinctly different and easily distinguishable.
_Width._--All shoes should be wider at the toe than at the ends of the branches. The average width should be about double the thickness of the wall at the toe.
_Thickness._--The thickness should be sufficient to make the shoe last about four weeks and should be uniform except in special cases.
_Length._--This will depend upon the obliquity of the hoof viewed in profile. The acute-angled hoof (fig. 5a) has long overhanging heels, and a considerable proportion of the weight borne by the leg falls in the posterior half of the hoof. For such a hoof the branches of the shoe should extend back of the buttresses to a distance nearly double the thickness of the shoe. For a hoof of the regular form (figs. 5b and 8) the branches should project an amount equal to the thickness of the shoe. In a stumpy hoof (fig. 5c) the shoe need not project more than one-eighth of an inch. In all cases the shoe should cover the entire "bearing surface" of the wall.
_Surfaces._--The surface that is turned toward the hoof is known as the "upper," or "hoof surface," of the shoe. That part of the hoof surface which is in actual contact with the horn is called the "bearing surface" of the shoe. The "bearing surface" should be perfectly horizontal from side to side, and wide enough to support the full thickness of the wall, the white line, and about an eighth of an inch of the margin of the sole. The bearing surface should also be perfectly flat, except that it may be turned up at the toe ("rolling-motion" shoe, fig. 5 a, b, c.) The surface between the bearing surface and the inner edge of the shoe is often beaten down or concaved to prevent pressure too far inward upon the sole. This "concaving," or "seating," should be deeper or shallower as the horny sole is less or more concave. As a rule, strongly "cupped" soles require no concaving (hind hoofs, narrow fore hoofs).
_Borders._--The entire outer border should be beveled under the foot. Such a shoe is not so readily loosened, nor is it so apt to lead to interfering.
_Fullering._--This is a groove in the ground surface of the shoe. It should pass through two-thirds of the thickness of the shoe, be clean, and of uniform width. It is of advantage in that it makes the shoe lighter in proportion to its width and, by making the ground surface somewhat rough, tends to prevent slipping.
_Nail holes._--The shoe must be so "punched" that the nail holes will fall directly on the white line. They should be confined to the fore half of front shoes, but may occupy the anterior two-thirds of hind shoes. For a medium-weight shoe three nail holes in each branch are sufficient, but for heavier shoes, especially those provided with long calks, eight holes are about right, though three on the inside and four on the outside may do.
_Clips._--These are half-circular ears drawn up from the outer edge of the shoe either at the toe or opposite the side wall. The height of a clip should equal the thickness of the shoe, though they should be even higher on hind shoes and when a leather sole is interposed between the shoe and hoof. Clips secure the shoe against shifting. A side clip should always be drawn up on that branch of the shoe that first meets the ground in locomotion.
SPECIAL FEATURES AND FITTING THE SHOES.
_A shoe for a regular hoof_ (figs. 7 and 8) fits when its outer border follows the wall closely in the region of the nail holes and from the last nail to the end of the branch gradually projects beyond the surface of the wall to an eighth of an inch and extends back of the buttresses an amount equal to the thickness of the shoe. The shoe must be straight, firm, air-tight, its nail holes directly over the white line, and its branches far enough from the branches of the frog to permit the passage of a foot pick. Branches of the shoe must be of equal length.
In fitting a shoe to a hoof of regular form we follow the form of the hoof, but in base-wide and base-narrow hoofs, which are of irregular form, we must pay attention not only to the form of the hoof but also to the direction of the pasterns and the consequent distribution of weight in the hoof, because where the most weight falls the surface of support of the foot must be widened, and where the least weight falls (opposite side of the hoof) the surface of support should be narrowed. In this way the improper distribution of weight within the hoof is evenly distributed over the surface of support.
_A shoe for a base-wide hoof_ should be fitted full on the inner side of the foot and fitted close on the outer side, because the inner side bears the most weight. The nails in the outer branch are placed well back, but in the inner branch are crowded forward toward the toe.
_A shoe for a base-narrow hoof_ should be just the reverse of the preceding. The outer branch should be somewhat longer than the inner.
_A shoe for an acute-angled hoof_ should be long in the branches, because most of the weight falls in the posterior half of the foot. The support in front should be diminished either by turning the shoe up at the toe or by beveling it under the toe (fig. 5a).
_A shoe for a stumpy hoof_ should be short in the branches, and for pronounced cases should increase the support of the toe, where the most of the weight falls, by being beveled downward and forward.
In many cases, especially in draft horses, where the hoofs stand very close together, the coronet of the outer quarter is found to stand out beyond the lower border of the quarter. In such cases the outer branch of the shoe from the last nail back must be fitted so full that an imaginary perpendicular dropped from the coronet will just meet the outer border of the shoe. The inner branch, on the other hand, must be fitted as "close" as possible. The principal thought should be to set the new shoe farther toward the more strongly worn side. Such a practice will render unnecessary the widespread and popular fad of giving the outer quarter and heel calk of hind shoes an extreme outward bend. Care should be taken, however, that in fitting the shoe "full" at the quarter the bearing surface of the hoof at the quarter be not left unsupported or incompletely covered, to be pinched and squeezed inward against the frog. This will be obviated by making the outer branch of the shoe sufficiently wide and punching it so coarse that the nails will fall upon the white line.
_Hot fitting._--Few farriers have either the time or the skill necessary to adjust a cold shoe to the hoof so that it will fit, as we say, "air-tight." Though the opponents of hot fitting draw a lurid picture of the direful consequences of applying a hot shoe to the hoof, it is only the abuse of the practice that is to be condemned. If a heavy shoe at a yellow heat be held tightly pressed against a hoof which has been pared too thin, till it embeds itself, serious damage may be done. But a shoe at a dark heat may be pressed against a properly dressed hoof long enough to scorch, and thus indicate to the farrier the portions of horn that should be lowered without appreciable injury to the hoof and to the ultimate benefit of the animal.
_Nailing._--The horse owner should insist on the nails being driven low. They should pierce the wall not above an inch and five-eighths above the shoe. A nail penetrating the white line and emerging low on the wall destroys the least possible amount of horn, has a wide and strong clinch, rather than a narrow one, which would be formed near the point of the nail, and, furthermore, has the strongest possible hold on the wall, because its clinch is pulling more nearly at a right angle to the grain (horn tubes) of the wall than if driven high. Finally, do not allow the rasp to touch the wall above the clinches.
THE BAR SHOE.
The bar shoe (fig. 9) has a variety of uses. It enables us to give the frog pressure, to restore it to its original state of activity and development when, by reason of disuse, it has become atrophied. It gives the hoof an increased surface of support and enables us to relieve one or both quarters of undue pressure that may have induced inflammation and soreness. The bar of the shoe should equal the average width of the remainder of the shoe and should press but lightly on the branches of the frog. The addition of a leather sole with tar and oakum sole-packing allows us to distribute the weight of the body over the entire ground surface of the hoof.
THE RUBBER PAD.
Various forms of rubber pads, rubber shoes, rope shoes, fiber shoes, and other contrivances to diminish shock and prevent slipping on the hard and slippery pavements of our large cities are in use in different parts of the world. In Germany the rope shoe (a malleable-iron shoe with a groove in its ground surface in which lies a piece of tarred rope) is extensively used with most gratifying results. It is cheap, durable, easily applied, and effective.
In the large cities of England and the United States rubber pads are extensively used. They are rather expensive, but are quite efficient in preventing slipping on polished and gummy pavements, though not so effective on ice. Figure 11 is an illustration of one of the best of many rubber pads. The rubber is stitched and cemented to a leather sole and is secured by the nails of a three-quarter shoe. Such a pad will usually last as long as two shoes. They may be used continuously, not only without injury to the hoof, but to its great benefit. The belief, unsupported by evidence, that rubber pads "draw the feet" keeps many from using them. A human foot encased in a rubber boot may eventually be blistered by the sweat poured upon the surface of the skin and held there by the impervious rubber till decomposition takes place with the formation of irritating fatty acids; but there is no basis for an analogy in the hoof of a horse.
OTHER SPECIAL FORMS.
Some drawings, designed to illustrate shoeing in connection with "interfering" and "forging," and other special conditions, are shown in figures 13 to 18.
INDEX.
Abdomen-- dropsy, in foal, or ascites, description and treatment, 193 dropsy, or ascites, description, symptoms, and treatment, 86 limbs, and perineum, dropsy affecting, description and treatment, 180 sheath, and penis, swelling, cause and treatment, 171
Abnormal presentations at birth, 197-202
Abortion, description, cause, symptoms, and treatment, 182
Abscess-- and inflammation of lymphatic glands, descriptions, symptoms, treatment, 272 in lung and suppuration, symptoms, 127
Abscesses-- acute, description and treatment, 500 cold, description and treatment, 501 description, 500 in throat, treatment, 62
_Acari_, parasites of eye, 296
Acariasis, or mange, note, 478
_Achorion schönleini_, vegetable parasite of skin, description, 478
Adams, John W., chapter on "Horseshoeing", 583-605
Air embolism, or air in veins, note, 270
Albuminoid poisoning, hemoglobinuria, azoturia, azotemia, symptoms, prevention, and treatment, 141
Aloes, use against bots in horses, 93
Amaurosis, or palsy of nerve of sight, causes, symptoms, and treatment, 231, 295
Amnion, dropsy, description and treatment, 180
Anasarca, or purpura hemorrhagica, causes, symptoms, treatment, etc., 531, 533
Anatomy and physiology of brain and nervous system, 210
Anemia-- of brain, causes, symptoms, pathology, and treatment, 223 spinal, symptoms and treatment, 234
Aneurism-- description, symptoms, pathology, and treatment, 265 one form caused by _Strongylus vulgaris_, 265
Anidian monsters, or moles, description, 179
Animal parasites, description of kinds, 478
Ankle-- and fetlock, skin, note, 397 fetlock, and foot, diseases, chapter by A. A. Holcombe, 395-457
Ankles, cocked, or knuckling, description, causes, and treatment, 400
Anthrax-- definition, causes, symptoms, and treatment, 540-544 prevention by destruction of bacteria, 544 vaccination as preventive, 544
Apoplexy, or cerebral hemorrhage, causes, symptoms, pathology, and treatment, 220
Arteries-- description, 249 diseases, or arteritis, and endarteritis, description, symptoms, pathology, and treatment, 263
Artery-- constriction, description, 265 rupture, description, symptoms, and treatment, 266
Arthritis, open joints, broken knees, and synovitis, cause and treatment, 357
_Ascaris equorum_, intestinal worm, note, 90
Ascites, or dropsy of abdomen, description, symptoms, and treatment, 86, 193
Asthma, heaves, or broken wind, definition, symptoms, and treatment, 128
Atheroma of veins and arteries, description, 264
Autogenic vaccines, description, 506
Autumn mange, description and treatment, 480
Azotemia, hemoglobinuria, azoturia, poisoning by albuminoids, symptom, prevention, and treatment, 141
Azoturia, hemoglobinuria, azotemia, poisoning by albuminoids, symptoms, prevention, and treatment, 141
_Bacillus equisepticus_, cause of pneumonia, 522
Bacteria, kinds responsible for pneumonia in horses, 522
Bacteria vaccines, kinds and uses, 506, 531
Balls, or pills, description and manner of administering, 44
Bar shoe, uses, 601
Bees, wasps, and hornets, stings, treatment, 485
Beets as feed, 56
Bichlorid, use in disinfection, 509
Bighead (osteoporosis)-- chapter by John R. Mohler, 578-582 symptoms, lesions, and treatment, 580
Biliary calculi, or gallstones, symptoms and treatment, 90
Bilocular cavity, or calculus in sheath, or preputial calculus, description and treatment, 163
Birth, abnormal presentations at, 197-202
Black pigment tumors, or melanosis, description and treatment, 476
Bladder-- calculus, or stone, and tumor affecting, 190 diseases growths, symptoms and treatment, 151 eversion, description and treatment, 152 inflammation, cystitis, or urocystitis, symptoms and treatment, 149 irritable, cause and treatment, 150 neck, spasms affecting, causes, symptoms, and treatment, 146, 225 paralysis, description and cause, 230 paralysis, symptoms and treatment, 148 stone, vesical calculus, or cystic calculus, description, symptoms, and treatment, 159 worm of kidney, 146
Bleeding-- after castration, treatment, 170 from lungs, or hemoptysis, causes, description, and treatment, 127 from nose, causes and treatment, 103 or flooding from womb, treatment, 205 skin eruptions, or _Dermatorrhagia parasitica_, description and treatment, 469
Blisters, inflammation, or eczema, description and treatment, 464
Bloat colic, cause, symptoms, and treatment, 73
Blood-- circulation of heart, description, 248 clots in walls of vagina, 207 medicine administered into veins, 48 medium of disease transmission, 511 of penis, extravasation, cause and treatment, 167 spavin, bog spavin, and thoroughpin, description and treatment, 356
Blood vessels-- and heart, diseases, remarks, 250 heart, and lymphatics, diseases, chapter by M. R. Trumbower, 247-273 physiology and anatomy, 247
Bloody urine, or hematuria, cause and treatment, 141
Blowing, high, description, 110
Bluebottle (_Lucilia cæsar_), note 481
Bog spavin, blood spavin, and thoroughpin, description and treatment, 356
Boil of eyelid, description and treatment, 282
Boils-- or _Dermatitis granulosa_, 469 or furuncles, description and treatment, 466
Bone-- hip, fracture, or on innominatum, description, symptoms, prognosis, and treatment, 341 premaxillary, fractures, description and treatment, 336 spavin. _See_ Spavin
Bones-- cannon, fractures, description, symptoms, and treatment, 350, 395 cranial, fractures, causes, symptoms, and treatment, 335 diseases, description, 309 dislocations and luxations, cause, symptoms, and treatment, 361 of face, fractures, description, and treatment, 366 of fetlock and foot, description, 395 of hip, fractures, causes, 188 one system of locomotion, 299, 301 sesamoid, fractures, cause, symptoms, prognosis, and treatment, 352
Botfly, habits and treatment, 93
Bots, injury to horses, symptoms, and treatment, 93-94
Bowels, twisting, volvulus, or gut-tie, cause, symptoms, and treatment, 72