Second stage. Incision through the muscles and peritoneum and torsion of any small muscular arterioles, which may be divided.
Third stage. Fixation and immobilisation of the rumen with from four to six sutures (Fig. 303).
Fourth stage. Vertical incision into the rumen; manual examination of the cavity and its contents.
Formerly the operation was confined to these stages. In such cases localised adhesive peritonitis follows, causing the rumen to adhere to the internal surface of the abdominal wall, and the fistula continues in existence for months before complete cicatrisation. It is better, therefore, to insert sutures in the rumen, in order to secure more rapid and complete closure.
Fifth stage. Suture of the rumen with carbolised silk. The lips of the wound should be brought together face to face, or they can be slightly inverted, but the sutures should only pass through the peritoneum and muscular coats, avoiding the mucous coat. If the silk threads pass through the mucous membrane and come in contact with the gas in the upper zone of the rumen they are rapidly macerated, and the sutures tear out before the wounds can heal. The rumen should always be kept fixed to the abdominal wall towards the upper and lower extremities of the operative wound, in order to avoid displacement and occurrence of peritonitis. For a similar reason the passing of the silk sutures should be preceded by careful disinfection of the operative wound, and free washing of the parts with boiled water.
Fig. 304.
The operation is concluded by bringing the skin together with a few silk sutures and inserting a strip of iodoform gauze into the lower portion of the wound, to serve as a drain.
LAPAROTOMY.
Laparotomy is comparatively seldom performed on animals of the bovine species, though it may become necessary in dealing with cases of hernia, uterine torsion (where direct taxis is called for), Cæsarean section, invagination or strangulation of the intestine, and under a few other exceptional circumstances.