Impaction of the large bowels is to be diagnosed by a slight abdominal pain, which may disappear for a day or two to reappear with more violence. The feces are passed somewhat more frequently, but in smaller quantities and drier; the abdomen is full, but not distended with gas; the horse at first is noticed to paw and soon begins to look back at his sides. Probably one of the most characteristic symptoms is the position assumed when down. He lies flat on his side, head and legs extended, occasionally raising his head to look toward his flank; he remains on his side for from five to fifteen minutes at a time. Evidently this position is the one giving the most freedom from pain. He rises at times, walks about the stall, paws, looks at his sides, backs up against the stall, which he presses with his tail, and soon lies down again, assuming his favored position. The intestinal sounds, as heard by applying the ear to the flank, are diminished, or there is no sound, indicating absence of motion of the bowels. The bowels may cease entirely to move. The pressure of the distended intestine upon the bladder may cause the horse to make frequent attempts to urinate. The pulse is but little changed at first, being full and sluggish; later, if this condition is not overcome, it becomes rapid and feeble. Horses may suffer from impaction of the bowels for a week, yet eventually recover, and cases extending two or even three weeks have ended favorably. As a rule, however, they seldom last more than four or five days, many, in fact, dying sooner than this.
The treatment consists of efforts to produce movement of the bowels and to prevent inflammation of the same from arising. A large cathartic is to be given as early as possible. Either of the following is recommended: Powdered Barbados aloes 1 ounce, calomel 2 drams, and powdered nux vomica 1 dram; or linseed oil 1 pint and croton oil 15 drops; or from 1 pint to 1 quart of castor oil may be given. Some favor the administration of Epsom or Glauber's salt, 1 pound, with one-quarter pound of common salt, claiming that this causes the horse to drink largely of water, thus mechanically softening the impacted mass and favoring its expulsion. Whichever physic is selected, it is essential that a full dose be given. This is much better than small and repeated doses. It must be borne in mind that horses require about twenty-four hours in which to respond to a physic, and under no circumstances is it to be repeated sooner. If aloes has been given and has failed to operate at the proper time, oil or some different cathartic should then be administered. Allow the horse all the water he will drink. Calomel may be administered in half-dram doses, the powder being placed on the tongue, one dose every two hours until four doses are given.