From the NMC Newsletter "Udder Topics", August, 1997

Several surveys conducted during the last decade have shown environmental streptococci as a leading cause of both subclinical and clinical mastitis throughout the world.

Environmental streptococcal intramammary infections (IMI) tend to be short duration infections with only a few becoming chronic. The bovine mammary gland appears to be most susceptible to environmental streptococcal infections during the dry period and early lactation. Primiparous and multiparous cows both are commonly infected with environmental streptococci at calving and approximately half are associated with clinical signs. Rates of IMI and clinical cases increase during hot and rainy weather.

Each of these important infection characteristics or risk factors need to be considered when aiming specific management practices at controlling environmental streptococcal mastitis.

Source: Proceedings from "Udder Health and Management for Environmental Streptococci" Guelph, Ontario, June 1997, p. 36