Delayed passage through the birth canal in the face of a faltering placenta compromises oxygenation of the calf. Although the calf is able to breathe as soon as its nose passes the lips of the vulva, expansion of the chest is restricted by the narrow birth canal. This situation is seriously aggravated when continuous forced traction is applied. As soon as the calf's head has passed the lips of the vulva, traction should be interrupted, the nostrils cleared of mucus and cold water applied to the head.
Again, when the calf is completely delivered, primary attention is directed toward establishing respiration. Mucus and fetal fluids should be expressed from the nose and mouth by external pressure of the thumbs along the bridge of the nose and the flat fingers underneath the jaws, sliding from the level of the eyes toward the muzzle. The common practice of suspending the calf by it hindlegs to "clear the lungs", must be questioned. Most of the fluids that drain from the mouth of these calves probably come from the stomach, and the weight of the intestines on the diaphragm makes expansion of the lungs difficult. The most effective way to clear the airway is by suction.
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