The necessary precautions may be summarized as follows:
(1) Provide an elastic rubber ball and tubes furnished with valves to direct the current of air, as in a common Davidson syringe.
(2) Fill the delivery tube for a short distance with cotton sterilized by prolonged heating in a water bath.
(3) In the free end of the delivery tube fit a milking tube to be inserted into the teat.
(4) Sterilize the entire apparatus by boiling for 30 minutes, and, without touching the milking tube, wrap it in a towel that has been sterilized in a water bath or in live steam and dried.
(5) Avoid drawing any milk from the teats; wash them and the udder thoroughly with warm soapsuds; rinse off with well-boiled and cooled water, and apply to the teats, and especially to their tips, a 5 per cent solution of carbolic acid or lysol, taking care that the teats are not allowed to touch any other body from the time they are cleansed until the teat tube is inserted. It is well to rest the cleansed and disinfected udder on a sterilized pad of cotton or a boiled towel.
(6) The injecting apparatus is unwrapped; the teat tube, seized by its attached end and kept from contact with any other body, is inserted into the teat, while an assistant working the rubber pump fills the quarter as full as it will hold. The tube is now withdrawn and a broad tape is tied around the free end of the teat to prevent escape of the air.
(7) The teat tube, which has been carefully preserved from possible contact with other bodies, is dipped in the carbolic acid solution and inserted in a second teat, and the second quarter is inflated, and so with the third and fourth.
(8) The recumbent cow is kept resting on her breastbone, with the head elevated, even if it should be necessary to pack around her with straw bundles or to suspend the head by a halter. When lying on her side she is liable to develop fatal bloating and to have belching of gas and liquids, which, passing down the windpipe, cause fatal broncho-pneumonia.