Accidental laceration of the vaginal wall by an intravaginal thermometer as a calving detection device in a Japanese black cow.

An intravaginal thermometer was inserted into a 59-month-old Japanese black cow to predict calving. After calving, the thermometer penetrated the vaginal wall and could not be removed by farm staff. Surgery to remove the thermometer was successful. The cow left the animal hospital without hospitalization. In the follow-up, the cow remained healthy on the farm for more than one year and is now pregnant. No symptoms related to damage to the vagina or infection developed. This is the first case report of a vaginal laceration caused by an intravaginal thermometer in a Japanese black cow. Insertional vaginal devices may cause vaginal lacerations in cattle.