A Text-Book of Horseshoeing
by A. Lungwitz and John W. Adams Copyright 1897
4. Corns (Bruised Sole).
The expression “corns” is applied to nearly all bruises of the pododerm of the posterior half of the foot, with the exception of the frog, which are apparent to the eye as yellowish, reddish, or bluish-red discolorations of the horn of the sole and white line.
The surface of the pododerm (fleshy leaves and villi) is chiefly involved, and almost without exception there is rupture of small blood-vessels and an outpouring of blood between the pododerm and the horn. The blood penetrates the horn-tubes and causes the above-mentioned staining. By subsequent growth of horn these stained patches are carried downward, and are finally uncovered and brought to sight in paring the hoof.
The seat of corns is either on the fleshy leaves of the quarters, or on the velvety tissue of the sole in the angle between the wall and the bar, or on the fleshy leaves of the bars. Thus we distinguish corns of the wall, sole, and bars.
Corns affect chiefly the front hoofs, and more often the inner half than the outer. Unshod feet are seldom affected.
According to the intensity of the lesions we distinguish:
1. Dry Corns. — The red-stained horn is dry, and there is seldom lameness.
2. Suppurating Corns. — They are the result of intense bruising followed by inflammation. The pus is either thin and dark grayish in color, denoting a superficial inflammation of the pododerm, or yellowish and thick, denoting a deep inflammation of the pododerm. In the latter case a veterinarian should be called. Lameness is usually pronounced.
3. Chronic Corns. — In this case there is vivid discoloration of horn in all possible hues. The horn is either soft, moist, and lardy, or crumbling, cracked, and at times bloody. The inner surface of the horn capsule has lost its normal character, and is covered with horny swellings or nodules (Fig. 192, a). Sometimes the wing of the os pedis on that side has become morbidly enlarged and loosened. A short, cautious gait alternates with well-marked lameness; the latter appears whenever the shoe presses too firmly on the corn, or when the hoof becomes too dry.
The causes, aside from the form and quality of the hoofs and the position of the limbs, lie in injudicious dressing of the hoof and in faulty shoes. Too much trimming of wide and flat hoofs, excessive weakening of the quarters, sole, bars, and frog of all other hoofs, while the toe is usually left too long, are the usual causes. Shortening one quarter too much in relation to the other, so that the foot is unbalanced and the lower side overloaded, is a frequent cause. Hollowing the sole and bars excessively and unnecessary thinning of the branches of the sole in the search for corns are also causes.
Among faulty shoes we may mention those not level on the hoofsurface, trough-shaped, too short in the branches, shoes which do not completely cover the bearing-surface of the hoof, or whose bearing-surface at the ends of the branches is directed downward and inward so that the quarters are squeezed together when the weight is put on the foot. Insufficient concaving of the shoe is often an exciting cause of corns in flat feet and in those with dropped soles. A well-formed shoe which does not rest firmly upon the hoof, or which has been shifted as a result of careless nailing, may as readily cause bruising of the quarters as neglected shoeing. The latter causes, as a rule, corns of the sole. It is very rarely that corns are caused by stones fastened between the frog and branches of the shoe or in unshod hoofs by pebbles becoming wedged in the white line.
Dryness is particularly injurious to the hoofs, and is in the highest degree favorable to the production of corns. It renders the hoof stiff and inelastic, and first manifests itself by a short, cautious (sore) gait when the horse is first put to work.
Treatment. — First, removal of the causes, by restoring tho proper form to the hoof through shortening a toe which is too long (especially apt to be the case in acute-angled hoofs), cutting down quarters which are too high, and carefully removing all dead horn from the branches of the sole, especially in acute-angled hoofs.
Deeply digging out a small area of blood-stained horn is injurious. It is much better to thin the horn of the entire branch of the sole uniformly, in doing which we should avoid wounding the velvety tissue of the sole or drawing blood.
The proper shoe is the bar-shoe, except when both cartilages are ossified. The pressure should not be taken from the quarters unless they are sore.
When there is a suppurating corn, the shoe should be left off several days. A chronic corn should be protected continuously from pressure by the shoe. This is accomplished by using a bar-shoe with leather sole. A three-quarter shoe is not sufficient to properly protect a hoof affected with a chronic corn, if the animal must perform exacting labor on hard roads.
The care of the hoof consists in keeping it cool, moderately moist, and pliant.
5. Inflammation of the Heels.
Inflammation of the bulbs of the plantar cushion (heels) is usually caused by such external influences as bruising. It occurs in both shod and unshod feet. The symptoms are: increased warmth, pain and swelling, sometimes infiltration of the tissues with blood, accompanied by a short, cautious gait, or, if only one foot is affected, by well-marked lameness.
The most frequent causes are: going barefoot upon hard (frozen), uneven ground; shoeing hoofs having low heels with flat shoes that are too short; sometimes too much frog-pressure by the bar of a bar-shoe; forging and grabbing.
The treatment first indicated is a cooling application in the form of an ice-poultice, or a soaking in cold water. Later, astringent (drying) applications are of benefit, especially if the perioplic horn-ring has partially loosened from the bulbs of the heels; for example, a weak solution in water of sulphate of copper (1 to 20), followed by the application of a shoe with heel-calks, which is quite long in the branches and which must not press upon the wall of the quarters.
6. Laminitis (Founder).
By this name we designate a peculiar inflammation of the pododerm at the toe. It arises suddenly in well-nourished and apparently healthy horses, following excessive work or long-continued rest in the stable, and frequently leads to a decided change of form of the hoof.
The disease is always accompanied with intense pain. It most often affects both front feet, more rarely all four feet, or only one foot. In the first case the two front feet are planted far in advance of the body, and the hind feet well forward under the belly. When all four feet are affected, travelling is exceedingly difficult, often impossible; in this case there is nearly always a high fever over the entire body.
The seat of the disease is in the fleshy leaves about the toe, more rarely upon the side walls and quarters. Depending upon the intensity of the inflammation, the fleshy leaves are more or less loosened from the horny leaves, as a result of which there is a change of position of the os pedis, with a simultaneous sinking of the coronet at the toe. This produces a change of form of the hoof. The quarters become higher. Rings form upon the wall, and their course is quite characteristic of the disease. At the toe these rings are quite close to one another, but as they pass back towards the quarters they gradually separate from one another and recede from the coronary band (Figs. 193, 194, and 195).
The wall at the toe is sunken just under the coronet; its lower part, on the contrary, is thrust forward. Later, the white line becomes pathologically widened. The horn of the white line is dry, crumbling, and easily broken down, so that a break in continuity (crack) is apt to occur between the wall and sole, and lead to the formation of a hollow wall (“seedy toe”). Where the inflammation is moderate and is not repeated, healing usually takes place and the horn grows down regularly and in normal direction from the coronet. However, a rather brittle condition of the horn remains permanently. If, on the contrary, the inflammation was very severe or repeated several times, the horny sole becomes flat just in front of the point of the frog as a result of the sinking of the os pedis, or it may even drop below the level of the wall (full hoof, dropped sole). Indeed, it even happens at times that the toe of the os pedis perforates the horny sole just in front of the point of the frog. The wall at the toe, which was previously but little altered in form, is now thrust prominently forward.
The inflammation of the pododerm may under certain conditions and by skillful veterinary treatment be removed, so that the characteristic changes of form and quality of the hoof will not occur. But if this is not accomplished, as is often the case, the disease will be obstinate, and permanent morbid changes of the horn capsule take place.
A horse in such a condition can be used, but the gait will be short and stiff. The hoofs are shuffled forward and set heels first to the ground, a manner of travelling that rapidly wears away the branches of the shoe.
In dressing a foundered hoof the outer circumference of the sole is the guide. The thick projecting wall at the toe may be removed with the rasp without injuring the foot. The sole should be spared, but the quarters should be lowered to improve the setting of the foot to the ground.
The choice of the shoe will depend upon the shape and nature of the sole. If this is still concave, an ordinary shoe may be used. If, however, the sole is flat or dropped, it must be protected by an open shoe with a broad web, or with a bar-shoe (Fig. 197), which is of especial value when the bearing-edge of the wall is weak or broken away.
As long as there is pain on pressure about the toe there should be no toe-clip, but two side-clips. The wall between these clips should be lowered a tenth to an eighth of an inch to prevent pressure of the shoe upon the sensitive tissues of the toe (Fig. 195). The nails should be as small as possible and placed well back towards the quarters. No nail should be driven in the wall at the toe when there is separation of sole and wall at the toe (hollow wall, seedy-toe).
The shoes of horses affected with founder often work forward as a result of the animals travelling upon their heels. To prevent this evil, clips may be raised at the ends of the branches of an open shoe, or one clip in the middle of the bar, in case a bar-shoe is used (Fig. 197).
7. Keraphyllocele (Horn Tumor).
A keraphyllocele is a more or less sharply bounded horn tumor projecting from the inner surface of the wall.
Its occurrence is rare. Its favorite seat is at the toe. It rarely causes lameness. It can only be diagnosed with certainty when it extends downward to the lower border of the wall. In this case there may be seen a halfmoon- shaped thickening of the white line which rounds inward upon the edge of the sole, and is of a waxen color. Frequently the horn at this place crumbles away, leaving a more or less dark-colored cavity from which there sometimes escapes a small quantity of dark-grayish pus.
Causes. — Chronic inflammation of the podophyllous tissue, resulting from compression or bruising. Keraphyllocele frequently follows a complete toe-crack of long duration, or a deep calk-wound at the coronet.
Prognosis. — Unfavorable, whether there is lameness or not. If there is no lameness it is very apt to arise later, and if lameness is already present it can only be removed by an operation, which should be performed by a veterinarian. A return of the lameness following hard work at a trot upon hard roads is always to be feared.
Shoeing. — An ordinary shoe well concaved underneath the inflamed region, which should be relieved of all pressure.
Should lameness persist, it will be necessary to remove a strip of the wall from the plantar border to the coronet in order to remove the horn tumor. The fleshy leaves which have secreted the tumor must be extirpated and the surface of the os pedis well scraped, or the growth will return.