Enteritis, or inflammation of the bowels, is one of the most frequently fatal diseases of the horse with which we have to contend. It may affect the large bowel, the small one, or both. It is the former in which the disease most frequently appears. As to the exact seat of the inflammation, there is no doubt that it commences in the lining membrane, and, with the continuance of the disease, extends outward, involving the substance of the bowel.
We are very much in the dark sometimes as to its causation. It may be a sequel to colic and impaction of the bowel, over-fatigue and exposure to vicissitudes of weather, wading through streams when heated by the chase, chemical irritants, vegetable poisons, strangulation, etc. None of these causes, however, are sufficient to account for all the cases of which the experienced veterinarian can speak; more often does he find, on the most careful inquiry and investigation, no clue whatever to the sudden appearance of the disease.
Although often described as simulating colic, there are marked distinctions to the observant. It may be, and often is the case, that abdominal pain, exhibited in the usual manner, first calls the attendant's notice to the patient. Rigors, or shivering, with coat staring, inappetence, accelerated breathing, great depression, and evacuation of very small quantities of dung, soon follows. The pulse, which in colic only quickens during the paroxysm of pain, is here persistently small, quick, and hard. The membranes of the eyes and nose are red and congested; the eyelid turned up shows the vessels to be full and standing-out. The mouth is clammy and tongue dry; the belly may be distended, but is much more frequently contracted - its altered shape is remarkable in a horse with whose outlines one is familiar, having the appearance of being pressed upwards and outwards. From the stage of dull listlessness the patient passes on to one of excitement, stamping the ground, and striking the belly very much in the manner of colic, with occasional uneasy watching and turning of the head towards the flank. In a great many cases we have watched throughout the attack there has been very little violence, more often an uneasy scraping with the front foot, the attendants not being able to realize the gravity of the disease, but supposing it to be a mild attack of gripes. There are no intervals of ease here as in colic, and rarely any desire for food or water; the thirst which accompanies high temperature in man is rarely present in horses. All, except in the stage of delirium, lie down with much caution, lowering themselves in fear, and in quite a different manner from the griped horse, which may throw himself violently upon the floor of his stall before one can get out of his way. The skin alternates between hot and cold, and patches of perspiration break out from time to time. The ears are cold and the legs variable, one cold and another warm, or three out of four may have a deathly coldness - deathly coldness, we have said, for the experienced hand distinguishes quite different sensations when feeling them, and when feeling the legs of, say, a newly-clipped animal, which are cold from exposure. The eyes become glassy and insensitive to light, the pupil dilated, lips pendulous, ears dropped, the animal sighs, and with difficulty retains his feet, finally staggering and falling, unable to rise again. Constipation is present throughout, and we must not be deceived by the information given at first, that he has had two or three evacuations. In the few cases that recover there is amelioration of the symptoms during the first few hours, the general surface-warmth is restored, and the bowels act somewhat freely; the anxiety of countenance passes off, the patient shows some interest in surrounding objects, and may partake of a little mash or other invalid diet provided.
While it must be admitted that the recoveries in cases of pronounced enteritis bear but a small proportion to the deaths, we must spare no effort, nor cease to use palliative measures so long as the animal is kept alive. Associated as it invariably is with constipation, it was formerly thought good treatment to administer purgatives. There is a common ground of agreement as to keeping down pain with anodynes, and opium or its alkaloids are chosen by most practitioners because the movements of the bowels are best controlled by them. Opium or belladonna in balls or as draughts, or hypodermic solutions of morphia, may be given with advantage. Warm compresses to the abdomen continuously applied, and enemas of warm water containing a small proportion of glycerine thrown into the rectum now and again, will prove serviceable, as will also small quantities of morphia mixed with lard when inserted into the same channel. An improvement may be noted without any action of the bowels, as they remain in a more or less torpid condition till considerable advance towards recovery is made. It is not advisable during convalescence to give an aperient, but to wait for restored function in the injured portion of the bowel. Soft foods, as bran mashes, pulped carrots, and linseed should be given when the appetite returns, and all dry forage removed beyond the patient's reach, a muzzle being used, if necessary, to keep him from eating his bed. With regard to bleeding, no rule can be laid down; it may be advisable in plethoric young horses in hard condition. If it is done at all, it should be in the first stage, for later on it will only add to the depression. Bread scalded with milk and given nearly cold is an excellent food if the sick animal can be got to take it, and a little sugar may be added as an inducement to him to do so, or a sprinkling of salt may be more attractive.
The intestines after death may be found affected in any portion, small or large, but, as we have already pointed out, the latter are by far the most common seat of the disease; a long piece of the canal may be discoloured and swollen, or patches of inflammation, with congested portions occurring between them, may be the form in which the disease exists. In certain forms of enteritis a jelly-like matter between the different layers of the intestine is observed, and the latter may be readily separated with the finger, as their natural cohesion is lost. The mortification which in the majority of cases affects the bowel results in poisoning of the blood, and the septic matter acting on the nerve centres causes death in a very short time.
PLATE XXVI. ARAB MARE: BOZRA By Pharaoh; dam, Basilisk. In the possession of Lady Blunt.