One method of supplementing the teat’s defenses throughout the entire dry period is by use of an internal teat sealant. An artificial internal sealant is available for use alone or in combination with an antibiotic infusion. This product has no antimicrobial activity and, therefore, is recommended for use alone only in the uninfected udder. Otherwise, internal teat sealants should be used in conjunction with dry cow antibiotic therapy. When used alone in uninfected quarters, this product has been shown to prevent significantly more new infections than using no treatment at all, and it has been shown to have equal, if not better, efficacy in preventing new infections, as compared to using antibiotic alone.
In the infected udder, or when the infection status is unknown, an antibiotic infusion is recommended. This may be accompanied by teat sealant and may be especially valuable for the longer dry period. Using the internal sealant in combination with an antibiotic prevents significantly more new dry period infections than using antibiotic alone.
While internal teat sealants are most commonly used in combination with intramammary antibiotics in North America, they are also approved for combination use in most European countries. The teat sealant meets all requirements for protection of the nonlactating gland for organic herds, but this is also dependent on individual countries’ requirements. It is paramount that the very best hygienic practices are adopted when infusing the teat sealant to prevent contamination of the mammary gland.
Dry cow products - external sealants
Another method to supplement the cow’s defenses is to apply an external sealant to teats by dipping. These products are adjuncts to antimicrobial infusion. External teat sealants presently do not have a long duration of persistency on teat ends. As long as the teat end remains covered, protection from bacteria entering the gland is provided. Thus, for continuous protection, they require visual inspection and reapplication (if required) every five to seven days throughout the dry period. Alternatively, routine use and reapplication can be targeted at times of increased susceptibility, namely the late (transition) dry period.
Total vs. selective dry cow therapy
Most herds have been shown to benefit by treating every quarter of every cow at drying off with an antimicrobial infusion. This blanket approach will reach all infected quarters, is more effective than selective treatment in preventing new infections early in the dry period, and does not require laboratory screening procedures to decide which cows and quarters to treat.