Bovine Herpes Mammillitis Outbreaks of Bovine Herpes Mammillitis (BHM) usually occur during the autumn and winter months. Cold temperatures activate the virus which causes the infection. Outbreaks may last between 6 to15 weeks.

Symptoms are raw, scabbed and painful teats. The virus may be spread from cow to cow by milking equipment or on the hands of milkers. Salves and ointments may become contaminated and contribute to its spread.