From the NMC Newsletter "Udder Topics", October, 1998

Teats of individual quarters that are selected to receive treatment must be clean and dry. Each teat end should be scrubbed thoroughly until clean with cotton soaked in 70% alcohol. Separate pieces should be used for each teat. If more than one quarter is to be infused, teats on the far side of the mammary gland should be disinfected first, then treated last, after the teats on the near side have been disinfected and infused.

During infusion, the cannula should not be inserted completely through the teat duct because this may damage teat duct keratin. The syringe or cannula tip should be inserted only a short distance (approximately 1/8 inch) into the duct while the therapeutic agent is being administered. Teats should be dipped in a germicidal teat dip after infusion. Single use of syringes and cannulas is essential. If special care is not taken in cleaning and sanitizing teats prior to infusion, microorganisms present on the end of the teat may be forced into the mammary gland, resulting in a more severe infection than the one for which treatment was intended. F If highly contagious microorganisms, such as Mycoplasma species, are present in the herd, disposable rubber gloves should always be worn during treatment, and the hands dipped in a sanitizing agent between animal treatments.

Teats should always be dipped in an effective teat dip, dried with a clean paper towel, then scrubbed with alcohol before administering therapy, and dipped again after treatment.

Source: "Current Concepts of Bovine Mastitis" (1996) p. 5