This inflammation of the foot, or laminitis, is chiefly confined to the sensitive laminae, or leaves, which unite the hoof wall to the parts within, and of these leaves those in front are 0 2 most seriously affected. These leaves number five or six hundred or more, and surround the front and sides of the pedal bone, the largest and most vascular being in front, and it is these which are involved most acutely. Congestion of these leaves, especially if acute, will produce symptoms like those of inflammation. The causes are : long-continued standing in one position, severe exertion on hard ground, derangement of the stomach or bowels by improper food, or as the result of inflammation of these, or super-purgation 5 a gross condition and want of exercise, injury to the foot, inflammation of the lungs, improper shoeing, etc. The fore-feet are those most frequently involved, though the hind-feet may also suffer, and in certain cases all the feet may be inflamed.
This is a most painful disease, and causes great suffering, from the fact that the inflamed parts are confined in a rigid horny box, which does not allow of any expansion for the swelling that takes place. The breathing and the pulse are much affected, and the horse shows signs of distress. To relieve the front part of the feet, if the fore ones are involved, the horse throws the fore-limbs forward, so as to place as much of his weight as possible on the heels, with the hind-feet well under the body for support. In this position he will remain fixed, as it were, and it is most difficult to induce him to move. Should the inflammation affect the hind-feet, these are also placed under the body; but the fore ones are thrown back, so as to relieve the latter as much as possible. When attempting to move the animal backwards, the condition of the feet is at once made apparent by the animal's unwillingness to move them, the body swaying back, but the feet remaining fixed to the ground. Attempts to lift one of the feet also cause the animal to evince great agony. In some rare cases the horse is lying down, and then there is great unwillingness to get up. The hoofs are burning hot, and tapping with a hammer or stick greatly increases the pain.
Laminitis is a very serious condition when acute, and may lead not only to serious deformity of the hoof, or its being shed, but even death may result. In congestion, or the less acute form of inflammation, the consequences are not so serious. In the latter it may suffice to take off the shoes, lower the wall of the feet by means of the rasp, so as to allow the sole and frog to bear as much of the weight as possible, and keep them in a tub of warm or cold water for some time, and poultice for a few days. It is a good plan to induce the horse to lie down, or even to throw him down if he will not do so voluntarily.
The floor of the stall or box should be laid with soft bedding or moss litter. Gentle exercise on soft ground should be allowed, as soon as the pain subsides. The diet should be sloppy mashes or gruel, and a mild laxative, such as a pint of linseed-oil, may be necessary. In an acute case, the same treatment has to be followed out, with the addition of an ounce or two of the bicarbonate of soda, two or three times a day, in the food; with scarification of the coronets with the lancet, and the administration of from ten to twenty drops of Fleming's tincture of aconite in a pint of water two or three times, at intervals of four hours. Care is required in working and shoeing the horse for some time after recovery, the soles being kept unpared, and the frogs allowed to come in contact with the ground.
When the inflammation becomes chronic - a very common sequel - the horse's action is more or less altered, the heels coming to the ground in a conspicuous manner, and in the stable the animal has a tendency to rest on the heels. The feet are also generally hotter than in a healthy condition, especially after movement, and they become more or less altered in shape, the soles becoming flatter, the heels deeper, and the front of the wall losing its straight oblique line; there are also characteristic rings, narrow and deep in front, wider and flatter behind. The feet are also more sensitive when travelling on hard roads, the knees being kept more or less straight. Separation often occurs between the wall, the sole, and the laminae, leaving a cavity containing powdery horn, and known as "seedy-toe." For this condition, treatment must be chiefly palliative; the horse should stand on tan or moss litter, and for some hours of the day in a stall laid with clay tempered with salt and water, or be allowed to run on moist meadow land. A mild blister may be applied round the coronet now and again, and shoeing be carefully performed.