Causes. The predisposing cause is the extreme mobility of the canine stomach which hangs from the œsophagus like a pear from its stalk, the remainder of the viscus being only attached to the loose omentum, spleen, and commencement of the duodenum all of which it can carry with it easily when it rolls on itself. Its mobility is, however, very restricted when full, the liver on the one side and the spleen and intestines on the other proving almost insuperable obstacles to rotation. But when empty it moves with great freedom and by a sudden shock in leaping, gamboling or running rapidly down stairs the pylorus is carried forward and to the left until it and the commencement of the duodenum are jammed in front of the cardia. The result is the obstruction of the cardia and duodenum by their mutual pressure in crossing each other, and the interruption of the gastric circulation and functions.
Lesions. As just stated the stomach which would normally extend from the cardia downward and to the right is bent forward and doubled upon itself, the pylorus lying in front of the cardia, the duodenum extending from before backward above the cardia and tightly compressing it, the liver drawn to the left by the hepato-duodenal peritoneum, and the spleen displaced to the right by the traction on the omentum. The stomach enveloped in its omentum is distended by gas to perhaps ten times its normal dimensions and appears to fill the entire abdominal cavity while the intestines are pushed aside and concealed. The chest is compressed by the strong pressure on the diaphragm, and the lungs are congested of a deep blue and the right heart distended with dark blood. The animal appears to have perished of apnœa.
Symptoms. In fully developed cases the abdomen is greatly distended and tympanitic. The drumlike resonance is met with in the anterior part of the abdomen including the umbilical region. It extends forward over one-half of the thorax, excepting only a space of 5 or 6 inches square in the right hypochondrium, which represents the situation of the liver, and spleen. Auscultation furnishes no sound in the abdomen, and only in the anterior portion of the thorax is there a distinct respiratory murmur. The heart may beat strongly and rapidly, or weakly and slow, and the pulse is small and thready. The abdomen is tender. The animal stands, dull, and breathes with great effort. If made to walk it is done slowly, stiffly and with head extended, mouth open and tongue protruding. There is no sign of vomiting and this cannot be brought about by tickling the fauces, or even by giving apomorphine subcutem, though retching may be induced.
Course. The disease may develop into dullness and anorexia in two hours after boisterous health; in twelve hours there may be considerable tympany and dyspnœa; and a fatal result is reached in about thirty-six hours.
Diagnosis. This is based on the transition from vigorous health to sudden illness, with complete anorexia, inability to swallow or to vomit, tympany of the stomach as shown by percussion, tenderness of the abdomen, dyspnœa, disturbed heart-functions, and inactivity of the bowels. With intestinal obstruction on the other hand there is free vomiting of bilious and feculent matters. With peritonitis there is much greater and more uniform abdominal tenderness, vomiting and higher fever, but less tympany in the anterior abdominal region, and no such complete suspension of defecation. With choking there is no such progressive tympany, appetite and defecation are not so completely suspended, and liquids may often pass the obstruction in small quantities in both deglutition and vomiting. Choking is by no means so speedily fatal.
Treatment is essentially surgical. When tympany is already established the gas must be evacuated by a small cannula and trochar. Then resort is had to laparotomy, the incision is made on the right side large enough to introduce the fingers, which must follow the great curvature of the stomach as far as the pylorus which is pulled back into its normal position on the right. The incision is now closed by an ordinary continuous suture.
FOREIGN BODIES IN THE STOMACH. HAIR, WOOL, BRISTLE, CLOVER AND COTTON BALLS.
Hair balls, wool balls, bristle balls, cotton balls, clover-hair balls, oat-hair balls, paper balls, phosphatic calculi, sand and gravel, nails, wires, needles, pins, etc., cloth, leather, whalebone, playthings, etc. Symptoms: of catarrh or colic, dullness, restlessness, arched back, in dog vomiting of blood, fistula. Diagnosis. Treatment: emetic, feed potatoes, laparotomy.
Hair Balls. These are common in the rumen of cattle and have been found in the fourth stomach. They are especially injurious to young animals by reason of their irritating the gastric mucosa, but they also occasionally block the pylorus, producing indigestion, gastric dilatation, gradually advancing emaciation and even a fatal result.
Wool Balls. These are found in sheep and are especially injurious in young lambs.