The treatment is exclusively surgical, and the hernia can be reduced and castration performed at one and the same time. The animal being placed on its back and firmly held, an incision of about 2 to 3 inches in length is made in the inguinal region, dividing the skin and subcutaneous connective tissue only. The vaginal sheath is then completely isolated, the hernia reduced, and a ligature applied to the sheath and the spermatic cord close to the abdominal wall. The testicle is then removed.
If adhesions have been set up, which is quite exceptional, the vaginal sheath is incised and the loop of adherent intestine liberated, when it can readily be returned. The vaginal sheath and spermatic cord are then twisted as high as the level of the inguinal ring and tied with catgut. To prevent this ligature becoming displaced, it should be fixed by passing a sterilised thread through it and through the mass of tissue; the hernial sac should be divided immediately below. In order to ensure greater security, it may even be desirable to pass a suture through the margins of the inguinal ring.
UMBILICAL HERNIA.
Umbilical hernia is less common in young animals of the bovine, ovine and porcine species than in the foal, and when existing almost always disappears at the period of weaning. The rumen then assumes its full development, the loops of intestine are displaced and thrust towards the sublumbar region, and the hernia disappears. The same is true of the young pig, the development of the stomach producing the same favourable result.
In the rare cases where this hernia is not reduced spontaneously, it may be necessary to utilise the methods so frequently employed in the foal, and, despite the number of these, there are only two which can thoroughly be relied on to give good results.
In the first, irritants are employed.
Subcutaneous injections of concentrated solution of common salt, filtered and sterilised, or 10 per cent. solution of chloride of zinc produce enormous engorgement of the connective tissue, which thrusts back the herniated loop of intestine and later causes the development of very resistant fibrous tissue, which prevents the hernia returning.
To ensure this result, however, it is indispensable that perfect asepsis should be observed in the injections, for if germs are introduced severe suppuration occurs at the point of injection. The injections are made at four opposite spots in the subcutaneous tissue surrounding the hernia, 1 to 2 drachms of saline solution being injected at each spot; of the chloride of zinc solution half a cubic centimètre is used. This method is only of value in small herniæ, which may sometimes be cured by the application of sinapisms alone.
The second method is applicable to larger herniæ, and aims at destroying the hernial sac.
The application of clams is simplest, and can be recommended. The patient is placed on its back, reduction is effected, the hernial sac is drawn upwards vertically, and the clams placed as near the abdominal wall as possible, after care has been taken that no portion of the intestine is included in the sac. The clams are kept in place by a suture passed through the neighbouring tissues.