Such paresis and indigestion, however, are more common as the result of a general debility or a special gastric atony caused by disease, starvation, overwork or fatigue. In all acute febrile and inflammatory diseases the gastric functions are weak or suspended, and if the animal is tempted to eat, the ingesta is unaffected by the digestive fluids and forms a suitable fluid for injurious fermentations. In convalescence especially, when the starved system once more craves support, tempting food is liable to be taken to excess, unless the attendant is especially judicious and careful in grading the feed as the stomach can dispose of it. The horse that has been starved must be fed little and often, of easily digested material until the gastric functions are restored. Long continued severe work, exhausts the motor and secretory power of the stomach, as it debilitates the system at large, and the animal may be at first unable to digest a feed of grain even if he will take it. In such a case as in that of the very hungry glutton a drink of gruel or a handful of hay which he must masticate will often obviate the danger. Violent exertion immediately after a meal arrests digestion, and tends to a fatal indigestion. An animal fed grain and immediately put to severe work, or subjected to confinement for a painful operation, may die in two hours from tympanitic indigestion. This weakness of the digestion may come from profuse bleeding, from the anæmia caused by parasites (sclerostomata), or from injuries to the pneumogastric nerves or their centres. It can be produced experimentally by cutting both vagi; the gastric contents then remain packed and solid, without peptic juices and without digestion. Iced water, like frozen food, may temporarily arrest the gastric functions and entail fermentation. It acts most dangerously on the overheated and exhausted horse, and though the indigestion may not prove fatal, it may induce a sympathetic skin eruption or laminitis. The mere exposure to external cold is less to be dreaded as there is a compensating stimulus which drives the blood to internal organs, the stomach included. Standing in cold water or wading or swimming a cold river, is commonly less injurious than a full drink of iced water, when heated and fatigued.