“To use a trocar and cannula, proceed as follows: Tie the animal so it cannot get away. With a sharp knife, make a small incision through the skin over the prominent part of the swelling on the left side. This incision should be made about half way between the point of the hip and the last rib, and should be large enough to admit the trocar and cannula readily. The incision should be made quickly; then the animal will not notice it. After the incision is made the trocar and cannula are pushed quickly in and directed downward, inward, and forward; push the trocar in until the flange of the cannula rests against the skin. Withdraw the trocar and the gas will rush out; that is, it usually does so; occasionally, however, the end of the cannula is plugged up with green food. This can usually be remedied by pulling out the cannula part way, or pushing the trocar in again and withdrawing it. If this doesn’t work, tap the stomach again in another place, using the same hole through the skin. The escape of gas is usually accompanied by a small quantity of green food. [Illustration: Trocar and Cannula] “If a trocar and cannula are not available in an urgent case, a knife can be used very successfully--a good-sized pocket knife blade, pushed quickly through the skin and muscles, in the same manner as described for the trocar and cannula. Care must be taken that the sharp edge of the blade is not turned towards the animal’s tail, as it sometimes jumps forward, and a much larger hole is cut than was originally intended. “A careful and observing stockman of Colorado, who has had a large experience with alfalfa bloating, informs me that he prefers a moderately small, sharp butcher knife to either a trocar and cannula or a pocket knife. It gives relief quicker and with no bad effects. Sometimes, if the opening through the skin is small, made by a small knife, a quill or small tube is fastened in to keep the incision open, so the gas can escape. It is usually necessary to keep the incision open for several hours. The only bad result of tapping is that occasionally green food gets outside of the rumen into the abdominal cavity in sufficient quantities to cause inflammation and death; but if the operation is intelligently performed, these bad results are extremely rare--probably not more than one case in 100. If the weather is warm, care should be taken that flies do not bother the wound in the skin.