Slight diarrhœa does not affect the appetite nor general health, nor check improvement in condition. In the more severe and continued forms there is loud rumbling in the abdomen, loss of appetite and condition, a rapid small pulse, accelerated breathing, pallid mucous membranes, sunken glassy eye, and increasing debility even to an unsteady gait. Distension of the abdomen with pawing and other indications of abdominal pain may appear in bad cases. In the milder cases due to simple irritation and congestion there is no tenesmus, no excess of mucus, no formation of bubbles or froth in the stools, as occurs in active intestinal fermentation and dysentery. In symptomatic cases on the other hand there are superadded the marked symptoms of intestinal inflammation, or fermentation, and the fæces become putrid and offensive, which they do also in the different infectious diseases (influenza, contagious pneumonia, rinderpest, lung plague, hog cholera, swine plague, canine distemper, fowl cholera), when the toxins and waste matters of the food and decomposing tissues are being thrown off by the bowels. Diarrhœa may be complicated with other diseases and especially in the horse with laminitis. In mild cases it tends to a spontaneous recovery, and is followed by some slight costiveness, and if this should prove extreme there may be some danger of complicating sequelæ such as indigestion, enteritis, pneumonia or laminitis. _Treatment._ The first consideration for the practitioner is to discover if possible the immediate cause of the diarrhœa. If this is found to reside in some infectious or other disease aside from the bowel, the attention must be directed to that even more than to the diarrhœa. If it depends on an overdose of some purgative agent or of acrid purgative plants taken with the food, any further laxative is to be avoided, and yet astringents and other agents which tend to lock up the offending material in the alimentary canal must be equally guarded against. An abundance of mucilaginous and demulcent liquids (mallow, flaxseed gruel, boiled starch, etc.) may be given both by the mouth and anus, to sheathe and protect the irritable mucous membrane and to dilute and carry off the irritant contents. Moderate doses of opium may be required to allay the violence of the spasms and peristalsis, but this should not be pushed to the extent of locking up the irritants. Sometimes antiseptics (naphthalin, salol) are useful to check fermentation, and pepsin may be given to assist digestion.