Evaluation of a teat dip of chlorhexidine digluconate (.5%) with glycerin (6%)

Efficacy of a teat dip containing .5% chlorhexidine digluconate and 6% glycerin was tested on 46 clinically normal cows, each with functional quarters. Twice daily immediately after milking, all teats were exposed to a suspension containing 5 X 10(7) colony forming units of Staphylococcus aureus. After each exposure to the infective broth, the left teats were dipped in teat dip while the right teats remained as untreated controls. The study continued until sufficient number of infections occurred to establish efficacy. Mastitis screening followed standard procedures as established by the National Mastitis Council and identified 24 infected teats in the control group and 6 in the treated group for 75% efficacy. The tested teat dip was effective in reducing the incidence of intramammary infections caused by Staphylococcus aureus under experimental exposure. No chapping or irritation occurred with use of the teat dip.