Seat and Lesions. The most common seat of invagination is in the small intestines, and less so in the cæcum and colon, or rectum. The lesions are as in the other animals, congestion, infiltration, adhesion, necrosis, gangrene and sloughing.
Symptoms. There may be colics as in the larger animals, but in some instances there are simply prostration, dullness, inappetence, vomiting, constipation, or the passage of a little liquid and fœtid excrement. Palpation of the abdomen detects a firm, cylindroid and very tender swelling on the line of the softer intestine which taken with the other symptoms is nearly pathognomonic. If situated in the small intestine and disconnected from the rectum and pelvis the diagnosis is more satisfactory. Impaction is most commonly in the rectum and floating colon and can be traced into the pelvis and even felt by the finger introduced into the anus. It might be confounded with obstruction of the intestine by the ingestion of twine, but the swelling is usually firmer and the cylindroid outline more uniform in intussusception.
Treatment. The measures recommended for the larger animals are applicable to the dog. Cadeac has had four recoveries in seven cases after the use of leaden shot and castor oil. Three balls of No. 16 calibre are dipped in castor oil and given to the dog. This is followed by ½ oz. of castor oil slightly heated, and walking or running exercise, or take the dog by his fore limbs and walk him around on his hind. No drink is allowed for 24 hours, and a quart of decoction of flax seed on the day following.
Should these measures fail, laparotomy is available, yet it is more promising in proportion as it is resorted to early, before ulceration, or gangrene has set in. The manipulations are practically the same as in the ox and the outcome is even more promising. The diet should be restricted to milk or mucilaginous gruels for a week after the operation.
VOLVULUS (TWISTING) OF THE INTESTINE IN SOLIPEDS.
Definition: rolling of a loop on its mesenteric axis, bending in a vicious direction, rolling of one loop round another. Causes: laxity of mesentery in hernia, relaxation or rupture of linea alba, pot belly in old breeding mares, sudden movements in falls, leaps, draught, galop, slipping, mounting, warm weather, casting, rolling, rising, sudden filling of a loop, heavy feeding and fermentescible food, cold drinks, chills. Lesions, most in double colon, next in jejunum, cæcum wrapped in small intestine, floating colon, tympany and pallor of obstructed loops, later congestion, infiltration, extravasation, adhesions, necrosis, sloughs, infective peritonitis. Symptoms: sudden severe attack, violent, reckless colicy movements, pain constant with exacerbations, fever, prostration, collapse. Diagnosis: only by rectal exploration and exceptionally. Treatment: by rectal manipulation, eserine, castor oil, laparotomy.
Strictly speaking this lesion consists in the twisting of a loop of intestine upon its mesenteric axis, so that the portion which is drawn spirally over the mesentery of the other is more or less completely obstructed. The term has, however, been applied as well to the turning of a viscus at a sharp angle from its normal direction so as to interfere more or less with the passage of its contents and with its circulation. This has been especially seen in a vicious direction given to the cæcum, but also at times to the double colon. The simple twisting on the mesenteric axis is common to the floating portion of the small intestines, the double colon, floating colon and rectum. A third form of twisting which is, however, rather a strangulation, consists in the rolling of one loop of intestine round the loop of another, the mesentery of which has become unduly long.
Causes. The predisposing cause is a certain laxity or undue lengthening of the mesenteric attachment of the intestine. This is sometimes formed in connection with the existence of hernia, into which the bowel protrudes, or short of this a relaxation or rupture of the linea alba so that the whole of the intestinal mass hangs down unduly, or finally in unthrifty pot-bellied animals and in breeding mares in which the abdomen is unduly pendent.
Next comes the question of sudden movement as in falls, in leaping, in violent exertions of draught, or galop, in sudden slipping upon wet or icy ground, and of stallions in mounting mares. In the Omnibus Company’s (Paris) horses Palat found 35 cases in entire horses, 23 in mares, and 11 in geldings. The stallions in the stables were fewer than the mares and geldings put together, but it does not appear that the difference was sufficient to make the above figures very significant. These stallions it should be added, are not used for breeding, so that the statistics have no bearing on the effect of mounting.
Palat’s figures show a greater number of cases in summer, than in winter. There were 58 cases from April to October and but 21 from November to March. It would seem as if the relaxation of the system and mesentery in summer more than counterbalanced the combined effect of slipping on ice and sudden chills.