The causes are various: the sudden application of cold either to the surface of the skin when hot, or to the intestines under similar circumstances, in the shape of cold water drunk hastily, and when the horse has been warm; in which latter case, the attack often soon follows. Costiveness will bring it on. Tumours in the mesentery, and strictures in the bowels are also the sources of occasional colic; and when a horse is found to be subject to repeated attacks, something of this kind, or otherwise calculous concretions, may be suspected: and I have known many instances where habitual colic was present, dependent on these causes. Horses long confined to dry food will sometime get it by suddenly gorging themselves with green meat; and with others, a constitutional tendency from some occult cause, gives them a predisposition to it. The symptoms of spasmodic colic are usually sudden in their appearance, and not marked, as in inflammation of the bowels, by previous indisposition; but the horse is observed to be at once attacked with considerable uneasiness, shifting his position from side to side, pawing his litter, and stamping with his feet impatiently. After a few minutes thus passed, the pain remits, and leaves the horse tolerably easy; while in enteritis no perfect remission occurs, but all is one scene of nearly equable pain and distress. As the colic advances, the remissions are less perfect, and less frequent: the horse now lies down frequently, and on rising shakes himself, looking round to his sides, which occasionally, in desperate cases, he snaps at with his teeth; but more frequently he is seen to strike with his hind feet at his belly, as though determined to remove by force the cause of his pain. In enteritis this acuteness of sensation or violence of temper is seldom seen. When on the ground, it is not uncommon for the horse to roll on his back; sometimes he will remain in this situation a few seconds, or he will roll over; neither of which are usually done in simple inflammation. In colic the pulse is seldom much altered from its natural state, unless the colic have existed some time, when it occasionally presents marks of general irritation, and is not only quickened, but also somewhat hardened. If felt also during the intensity of the paroxysms, it will likewise be often found to be disturbed even in the early stage, but this is momentary only, and ceases on the remission of the pain. The extremities, as the legs and ears, in colic are not often much affected, and they never remain intensely cold for a considerable period, as in enteritis; but the coat stares, and the horse breaks out frequently into cold sweats. In colic, also, relief is obtained by friction and motion, but both aggravate the distress in enteritis. Sometimes he is seen to attempt to stale without effect, at others he stales frequently, with momentary relief.