Teat open lesions can lead to challenges at milking time on dairies in the Northeast United States.

During evaluations of teat skin by the authors using National Mastitis Council procedures, teat open lesions (TOL) have been more commonly identified in dairies in the Northeast United States over the last 10 years. The TOL described here are found in all stages of lactation and in any age lactating cow, which is unique from TOL that present mainly in first lactation animals just after calving. Cows with these TOL exhibit more abnormal cow behaviors during the milking event. Based on the authors' subjective field evaluations, dry teat skin condition appears to be a significant risk factor. Although there is a paucity of published literature, the other risk factors that the authors have observed are exposure to wind and significant temperature fluctuations, wet bedding, certain bedding additives, and occasionally mechanical, chemical, or thermal trauma. Teat open lesions have been observed in herds with all the common types of bedding. Treatment and preventative measures have focused on supporting skin conditions through higher emollients in the postmilking teat disinfection (PMTD) and controlling the environmental conditions to which the teat is exposed. This includes an evaluation of cow positioning in the stall as well as bedding levels, which influence bedding contamination. The accuracy of PMTD application can also have an influence. The objective of this narrative review was to search the current literature describing TOL, identify knowledge gaps, describe the authors' field experience with TOL on dairy operations in the Northeast United States, and identify opportunities for future research.