By Jeffrey S Graybill
Agronomy Extension Educator
Perilla mint contains ketones that cause acute respiratory distress syndrome in cattle (ARDS), also called panting disease, which is often fatal.
Perilla Mint, (Peri indicutescens (L.) Britt.), also known as Beefstake plant, Purple Mint and Purple Perilla is a highly poisonous plant of the mint family. Sometimes grown as an ornamental, it can often be found growing in shaded or wet areas of pastures and along woodlot boundaries. Poisoning from Perilla are often a concern during the late summer and early fall when other grasses and forages might be in short supply. All parts of the plant are toxic however, it is reported to be especially toxic when flowering.
Cattle will normally not feed on these toxic weeds unless there is a shortage of other feed. Therefore, it is crucial to have a ready supply of quality feed available for farm animals during this time of the year. Walking your pastures and fence rows to find and identify this weed is very important. As much as possible, eradication and removal plants should be practiced.
A publication from the University of Tennessee states that Perilla Mint is the greatest cause of livestock death from poisonous plants in the state of Tennessee. It also contains additional information on identification and control of this noxious weed.