When the supply of food is greater than the work demands, the horse becomes fat. The superfluous nutriment is not all wasted. The system does not require it at the time, but it may at some other. To provide against an increased demand or a deficient supply, this redundant nutri ment is stored away. It is converted into fat and deposited into various parts of the body; some is laid under the skin, some among the muscles, but the largest quantity is found among the intestines and inside the belly. When wanted this fat is reconverted into blood.

Slow-working horses may be fat and yet not unfit for work; but the weight of the fat is a serious encumbrance to fast-workers, and its situation impedes the action of important organs, particularly the lungs Horses at full and fast work never accumulate fat; they can not oat too much. When the work is irregular and fast, the horse sometimes idle and sometimes tasked to the utmost, he may eat too much. He may become fat and unfit to do his work, which is the most ruinous of all work.

To keep a horse in condition for fast work, his work should be regular, and when it can not, his food should be given in such measured quantities that it will not make him fat.

A sudden change from a poor to a rich diet does not at once produce fatness. It is more apt to produce plethora, redundancy of blood. The stomach and bowels, previously accus tomed to economize the food, and to extract all the nutriment it was capable of yielding, continue to act upon the rich food with equal vigor. A large quantity of blood is made, more than the system can easily dispose of. Were the horse gradually inured to the rich food, there would be time to make the necessary arrangements for converting the superfluous nutriment into fat. But the sudden change fills the system with blood. This often happens to cattle and sheep, but the horse does not suffer in the same way as these animals. Sheep and young oxen, after entering a luxuriant spring pasture, take what is called the blood. All at once they become very ill; some part of the body is swelled, puffy as if it con tained air: in two or three hours the beast is dead. Upon dissection, a large quantity of blood, black and decomposed, is found in the cellular tissue, where, in life, the swelling appeared. This, if ever it occur in the horse, is exceedingly rare. In him, plethora seems to create a strong disposition to inflammation in the eyes, the feet, and the lungs.

Sometimes an eruption appears on the skin; this is termed a surfeit heat. The hair often falls off in patches, and the skin beneath is raw or pimpled; these are termed surfeit blotches. The horse is prone to grease. Those of the heavy-draught breed often have what in some places is termed a weed, in others a shoot of grease, in others still, a stroke of water-farcy. One of the legs, generally a hind-leg, swells suddenly; it is painful; it is lame; pressure inside the thigh in the course of the vein, produces great pain; the horse is a little fevered. In a few cases, among the same kind of horses, there are numerous puffy, painless tumors all over the body, especially about the eyes, muzzle, belly, and legs. This is most commonly termed water-farcy. The proper name is acute anasarca. The horse may be left well, or apparently well at night; in the morning he is found with his eyes closed, buried in soft pitting tumors, and his muzzle so much swelled that he can not open his mouth. All these evils are sudden in their attack.

They may arise from other causes; but plethora suddenly attained is the most common cause; and is the result of feeding beyond the work.

Plethora may be produced without any alteration in the quantity or quality of the diet. If the horse be suddenly thrown out of full work, and receive all the food to which he has been accustomed, the result will be very nearly the same as if he were put upon a richer diet. It must be remembered that excess in the supply is excess only when it is greater than the work demands. An idle horse may be eating no more than a working horse, or he may be eating less, yet it may be too much.

The symptoms of plethora are easily recognised before it has produced or contributed to the production of any cutaneous, anasarcous, or inflammatory disease. For one, two or more days the horse is somewhat dull; he eats his grain, perhaps, but refuses his hay; he drinks much, his coat is dry; on some places, across the loins, the face, and the poll, it is soft and staring; the eye is red, often yellowish; the mouth hot and dry; the bowels costive; the urine high-colored. When the stables are shut, the horse sweats; when open, he shivers, or his coat starts on end. If put to work, he is feeble and without animation; he soon perspires, and he is soon exhausted. In this febrile state he may remain for several days. Perspiration seems to relieve him a little; but as the horse eats little, the natural cure is probably performed by refusing to take more nutriment till the superfluity be consumed. When the digestive organs continue to maintain their power, the appetite is not impaired, and the horse, after pining two or three days, or a longer time, in the plethoric fever, suffers from an attack of inflammation, or some of the other evils already mentioned fall upon him.

Swelled legs and thrushy frogs are among the earliest and least serious consequences.

The treatment of plethora is very simple. Starvation alone will effect a cure. Bleeding averts its consequences at once; but, in general, this operation is not imperiously demanded. In ordinary cases, it is enough to diminish or withhold the allowance of grain, to give a little green food, carrots, or bran-mashes; as medicine, a diuretic or an alterative may be given, or a dose of physic, which is better than anything else and when the horse can be spared, it should be given. A gentle sweat is also a good remedy. As the horse recovers his spirits, let him return by degrees to the diet which his work demands.

To prevent plethora, it is customary, in hunting and other stables where the work is only occasional, yet very severe and requiring a liberal diet, to give an alterative now and then. Black antimony, nitre and sulphur, four drachms of each, form a useful alterative for blank days. Hunters of keen appetite, and legs which will not stand full work, are not easily kept in order: they may have a ball every week, or twice a week during the working season. It should bo given an hour before the last feed, in a little bran-mash. On the day before work, it is forbidden.

Influenza and plethora* are often confounded. The symptoms of plethora are very like those which we have at the beginning of influenza ; but the treatment is different, and distinction must be made. If the symptoms of plethora appear without any change in the diet, or work sufficient to account for them, it is very likely the horse is taking the influenza, which, in many stables, is usually called the distemper. A veterinarian ought to be consulted. Influenza is in general accompanied by great weakness, often some soreness of the throat, a little cough, a watery discharge from the nose, swelling of the eyelids, stiffness, a peculiar state of the pulse, and several other symptoms by which the veterinarian can distinguish it from plethora.