Finally all forms of gastritis—catarrhal, toxic, and phlegmonous—induce atony, fermentation and indigestion.
Symptoms. There may be simply tardy digestion or grave disorder with impaction or tympany.
In the former case there is impairment or perversion of appetite, refusal of food, irregular feeding, licking earth or lime, or eating filth, even fæces, with some dullness, apathy, or signs of pain such as pawing with the fore feet, or looking round at the flanks. There is rumbling of the bowels, followed in favorable cases by the passage of flatus, of softened fæces containing imperfectly digested food, and distinct diarrhœa which proves curative.
The more violent attacks set in suddenly, usually within one or two hours after feeding. There are usually colicy pains, pawing, looking back at the flank, kicking of the abdomen with the hind feet, lying down, rolling, rising again quickly, yawning, anxious pinching of the countenance, rigid loins insensible to pinching, and heat and dryness with an acid odor in the mouth. There is soon observed some swelling and tension of the belly with tympanitic resonance on percussion in the left hypochondrium. There is no elevation of temperature as in gastritis, and no complete intermissions of pain as in spasmodic colic, but pain is continuous, though worse at one time than another. There is an utter indisposition to eat or drink and if liquids are given by force there is manifest aggravation of the sufferings. As a rule there is no rumbling of the bowels, and though the animal may strain violently, little or nothing is passed, except at the first a few moulded balls of dung. The bowels like the stomach are paralyzed. In some cases there are attempts at regurgitation, the fore feet are placed apart, the neck arched, the lower cervical muscles are contracted and the nose drawn in toward the breast. In some instances relief is obtained by belching gas or by actual vomiting of solid matters. Vomiting in the horse is always ground for suspicion, since it usually occurs when the muscular coat of the stomach is ruptured. An important hindrance to vomiting lies in the loose folds of the mucosa covering the cardia, in the flaccid condition, and as these folds may be entirely effaced in hernia of the mucosa through the muscular coat as well as in the overdistended condition, vomiting may be either a fatal or a favorable indication. If vomiting takes place, without attendant prostration and sinking, and if on the contrary there is manifest improvement after it, it may be looked on as a beneficent outcome.
If no such relief is obtained the patient becomes increasingly dull and stupid; the breathing is accelerated, short, moaning or wheezing; the nostrils dilated; the nasal mucosa dark red; the superficial veins, especially those of the face, are distended and prominent.
The nervous symptoms may vary. Usually the dullness increases to stupor, the animal rests his head on the manger or against the wall, or if at liberty he may move forward or around blindly until some obstacle is met and he stumbles over it or pushes against it. In some instances there is champing of the jaws, or irregular motions of the limbs, but more commonly the dullness goes on to stupor and coma, the animal falls helpless and dies in a state of profound insensibility.
If the stomach should become ruptured there is often vomiting, the ingesta escaping by the nose, without any relief of the general symptoms, but with an increasingly haggard expression of countenance, sunken eye, and accelerated, weak, and finally imperceptible pulse. Cold sweats, which may have been already present, become more marked and the prostration becomes more extreme and the abdominal tenderness more marked. There are muscular tremblings of the shoulders and thighs, dilatation of the pupils, rapid breathing and stupor which presages death.
Recovery may be hoped for if rumbling in the bowels commences anew, if defecations continue and become soft and liquid, if urine is passed abundantly and if the general symptoms are improved. Complete relief may be had in five or six hours, and even in protracted cases in two days.
Lesions. The body is swollen, tense and resonant; the rectum usually projects somewhat and is dark red; the intestines, small and large, are tympanitic; the stomach is double or triple its usual size, tense and resistant, and with its contents may weigh as much as 40 pounds. When cut open its contents are seen to be disposed in the order in which they were eaten, in stratified layers, the motions of the stomach have not operated to mix them. There is no sign of digestion, unless it be in a thin surface layer or film which may be white, pulpy and chymified. The cuticular mucosa is usually unchanged further than its attenuation by stretching, the alveolated mucosa also attenuated is congested, opaque or slightly inflamed. The great curvature may be the seat of a rupture the edges of which are slightly swollen, congested and covered with small blood clots. The escaping ingesta usually remains enclosed in the omentum, which thus looks like a larger stomach with extremely thin gauze-like walls. If this is ruptured then the food floats in masses among the convolutions of the intestines. The peritoneum is red, hemorrhagic and covered with more or less exudation.
Another occasional lesion is rupture of the diaphragm. The liver and spleen are usually small and comparatively bloodless, owing to the compression.