Application of ear tags in cattle is a common husbandry practice for identification purposes. While it is known that ear tag application causes damage, little is known about the duration and process of wound healing associated with this procedure. Our objective was to quantify the wound healing progression in dairy calves with plastic identification tags. Calves (n=33) were ear tagged at 2 d of age and wound photos were taken weekly until 9–22 wk of age. This approach generated 10–22 observations per calf that were analyzed using a novel wound-scoring system. We developed this system to score the presence or absence of 8 different tissue types related to piercing trauma or mechanical irritation along the top of the tag (impressions, crust, and desquamation) and around the piercing (exudate, crust, tissue growth, and desquamation). Ears were scored as undamaged when tissue was intact. We found that wound tissue types associated with damage were still seen in many calves for at least 12 wk and up to 22 wk. This prolonged healing suggests extrinsic factors, such as mechanical disturbance and irritation, may have contributed to the wounds. Indeed, mechanical impression wounds, likely caused by the tag rubbing against the ear, were observed for the full duration of the study. Further research is warranted to understand ways to improve this form of animal identification.