Good teat disinfectants should have four major characteristics: 1) they should be effective against major mastitis pathogens, 2) be economical, 3) be easy to apply, and 4) should maintain or promote good skin condition. The active ingredient in most household laundry bleaches, sodium hypochlorite, is an excellent antibacterial agent, is economical, and easy to use. However, these products fail in three significant areas: 1) they are very harsh on the teat skin and can cause skin chapping and cracking and even increase new intramammary infection rates; 2) they have not been tested for use as a teat disinfectant, and 3) they are not approved by the FDA for use as a teat disinfectant. The label makes no reference to its being used as a teat dip. However, some of the first research into the benefits of teat dipping used Clorox, mixed 4 parts Clorox and 1 part water. Also, it was used in some of the early work with pre-dipping where it was mixed 1:1. It can cause chapping if started in cooler temperatures, and it is hard on clothes. The latter cost may offset the savings from the Clorox.

There have been few studies attempting to compare the effectiveness of sodium hypochlorite, the active ingredient in bleach to other teat dips. Sodium hypochlorite has not been shown to have as strong an association with reduced mastitis in observations of many different herds, or the same reduction of mastitis in teat dip trials, as some other teat dips. It has also performed better than some other teat dip formulations. It is certainly true that sometimes teat skin irritation and usually creating holes in clothes are associated with sodium hypochlorite also.

Dave Wilson, Utah State University Dairy Extension Veterinarian