The animal should be cast.
First stage. A V-shaped incision ¾ of an inch long on each side is made through the skin and subjacent tissues, exposing the bone.
Second stage. The skin and periosteum are dissected away and reflected upwards.
Third stage. Trepanation.
The lower portion of the cavity is trephined within the angle formed by a transverse line uniting the upper margin of the orbits and the inner margin of the super-orbital foramen.
The stages are precisely the same as those above described.
MAXILLARY SINUS.
In adult animals the maxillary sinus is opened immediately above the maxillary tuberosity. In the young the point selected is ¾ of an inch higher.
TRACHEOTOMY.
In bovine animals tracheotomy is only performed in urgent cases, in order to ward off asphyxia or to facilitate some other operation on the upper air passages. It is performed exactly as in the horse, the animal either standing or lying down. In the former case, the animal may be placed in the trevis, but two strong assistants holding the animal’s head and nose by means of “bulldogs” are often sufficient.