More California calves suffered from infection with Mycoplasma bovis during March than any other month of the year, according to research in the September 2004 Journal of Veterinary Diagnostic Investigation. The chart below shows the number of calves that were positive for M. bovis by month.

A higher incidence of calf myco-plasma in late winter and early spring may be associated with a higher rate of mastitis during this time. Calves can contract M. bovis by drinking milk from cows infected with myco-plasma mastitis.