This word is synonymous with overexerted, over-done, over-driven, distressed, and blown. All are applied, indifferently, to congestion of the lungs, to spasm of the diaphragm, and to excessive fatigue.

Congestion of the Lungs does not occur all at once. It is the consequence of keeping the horse too long at a fast pace, or at the top of his speed. The first symptom is difficult breathing. It. becomes remarkably quick and short; the nosnils are widely dilated; the horse frequently stretches out his head, as if he wanted more rein, yet goes no faster when he gets it; at intervals, short or long, according to the degree of congestion, he makes a deep, rapid inspiration, like a hurried sigh; the rider feels this though he can not hear it; his knees are thrown apart by the expansion of the chest. When these symptoms are apparent, congestion has begun in the lungs. If the horse be now pulled up, or even if his pace be slackened, he recovers his breathing in a little time, varying according to his condition, the depth of his chest, and the degree of congestion. Many horses become sulky and refuse to proceed any further; but the great majority of those employed at fast work can be urged on till they are seriously injured or destroyed. The horse, the camel, and the rein-deer, are, perhaps, the only animals that will kill themselves in the service of man. The dog, the ox,' the elephant, and perhaps the ass and mule, disregard the lash when it demands oppressive exertion.

But the horse has been so long and so completely subdued, that his obedience seems to have become hereditary.

If urged on after the first symptoms, the breathing becomes more difficult; the deep sigh and the protrusion of the muzzle more frequent. By-and-by the horse falters; his motions are sluggish, irregular, confused; he sinks often on his hind fetlocks, he staggers, reels, makes a running fall, and at last drops, or stands still gasping for breath. For a while before the horse is at his worst, he is so feeble that when put to a ditch or fence he is unable to clear it.

To prevent deadly or dangerous over-marking, the horse ought to be pulled up at the first sign of distress. If in good condition, he may recover his wind in a few seconds; if unprepared for such exertion, or if his chest be small, it may be several minutes ere he revive, and a very little will prevent him from proceeding any further.

When the distress is allowed to become very great, the horse must stop. Slacken the girths immediately, and take off the saddle. This is important: but some grooms have got a foolish notion that it is not right to remove the girths all at once in such a case. They say the wind will burst the horse. There is no need for argument here. I have repeatedly put the matter to experiment, and am perfectly satisfied that it is proper in every case to take the girths away as quickly as possible. Very often the horse recovers immediately, particularly when the girths have been drawn very tightly, as they mostly always are in hunting and in racing.

Let the horse stand with his head to the wind, take off the girths, and wait a little. He will get better presently, in five or ten minutes, and then he may be led home. He must be placed in a cold, airy stable; a warm or close one is very dangerous. If the breathing does not become easier in eight or ten minutes, the horse must be bled; but if, in this time, his breathing become tolerably quiet, bleeding may be delayed till the horse is stabled, and it will then be seen whether or not the operation is needful.

Bleeding, when properly managed, gives immediate and certain relief; but it is folly to bleed from the mouth in a case of this kind. Open the neck vein, and take away six or eight quarts of blood, as quickly as possible. As the skin cools, dry it, and apply clothes. After the bleeding, give six drachms of the carbonate of ammonia, powdered, and made into a ball with water and linseed-meal. Give the first three or four quarts of water quite cold, the rest tepid. Keep the legs warm, give a bran-mash, and open the stable windows.

Sometimes the horse reaches home before it is apparent that he is much the worse of his work. Perhaps he is stabled and dressed before it is observed that his breathing is still quick, that he does not eat, that his eye is red, his crest sunk, and flank tucked up. Put a finger upon the vein; if it do not rise, bleeding need not be tried. Give the carbonate of ammonia, and repeat it in an hour. Should the horse be no better at the end of that time, it is probable he will then bleed. The ammonia should make the blood flow. If livelier and the breathing easier, bleeding will not be necessary. Keep the legs and body warm; but give pure and cool air to breathe. Next day the veterinarian will see whether there be any danger of inflamed lungs, which is often the result of congestion.

Spasm of the Diaphragm takes place when the horse is at work, or it is observed whenever he is pulled up. His flanks heave rapidly; every fall is a convulsive jerk which shakes the whole body; a loud noise is heard, as if the heart were beating violently against the side. The diaphragm seems to be the seat of intermitting spasm. The action of the heart is always feeble and indistinct.

This affection is not very common. In a few cases it appears to exist independent of congestion in the lungs, but most frequently the two are combined. They are produced by the same causes. If the spasm do not cease in ten or fifteen minutes, give a dose of the carbonate of ammonia; and if the horse is not better in an hour, let him be copiously bled.

Excessive Fatigue is the result of a long rather than of a fast journey. The horse is very dull, his movements slow and stiff; he trips or stumbles at almost every step; when he gets home he eats little or nothing, lies much, is very restless, often changing his position; he drinks freely; sometimes he is a little fevered, the eye red and mouth hot. When there is no fever, the horse may have a cordial ball and his grain. When there is any sign of fever, a ball of the carbonate of ammonia is better; give a bran-mash, plenty of gruel, tepid water, only half grain, a good bed, a quiet stable, and rest for two or three days. On the second day the horse should recover his spirits and appetite. Stiffness remains for a few days longer: