Fig. 323.—Castrating knives.
This practice, however, has the disadvantage of sometimes causing the parietal peritoneum to strip away from the wall of the abdomen, which greatly increases the difficulties of operation. It is better, therefore, to grasp the peritoneum with a small pair of forceps, draw it outwards, and secure it so as to puncture it with more certainty. When experience has been acquired this precaution will be unnecessary.
The incision being made and the finger introduced into the abdomen, the operator, who kneels against the animal’s back, searches for the ovaries with his index finger. The upper ovary of the side in which the incision has been made will be found immediately in contact with the parietal peritoneum, and the operator must take care not to displace it by untimely or careless manipulation, which may thrust it away among the loops of intestine. The finger being doubled up in the form of a hook, the ovary is seized and drawn out. Sometimes it may be easier to withdraw the uterine horn, leaving the search for the ovary until a little later.
The first ovary having been discovered, its pedicle is seized between the left thumb and index finger or the jaws of pressure forceps, and then the search is continued for that of the opposite side. In young sows the horn of the uterus may be followed up from its extremity (ovarian extremity) towards its origin (bifurcation of the body of the uterus) and the search continued along the horn of the uterus of the opposite side, which is followed in the reverse direction from its base towards its extremity until the second ovary is found.
The most difficult stage is that at which the change is made from one horn to the other, for this is the moment when the contraction of the parts is most violent, the animal’s struggles most energetic and the pain most acute, so that great care must be taken not to let go the horn which has already been secured.
When the second ovary appears at the external orifice, it is secured like the preceding, and both are removed by torsion. The horns of the uterus are then freed and returned to the abdominal cavity, the wound is thoroughly disinfected and united with from one to three interrupted sutures passed through the skin. The animal is then allowed to rise. Complications are rare.
In small females the uterine horns are often removed by torsion along with the ovaries. In adults, only the ovaries are removed.
Subsequent Precautions: Operative Accidents.—The patients are kept on low diet for some days after operation. Accidental stripping away of the peritoneum at the seat of operation may sometimes result in the formation of a little abscess when the wound has been infected. This is diagnosed by direct examination or palpation. The lips of the wound are then opened in order to permit the pus to escape and avoid peritonitis. Should the horns of the uterus or the broad ligaments be roughly manipulated, they may be torn to some extent, but this rarely causes grave complications.
Bleeding from the incision in the abdominal wall is of little importance.