In dealing with these problems, it's important to understand how environmental streps work. Environmental streps generally include any strep not classified as Strep agalactia. This means that several organisms get lumped under one name. However, these organisms vary in source, and probably vary in their cure rates, and in their ability to infect. Not all-environmental strep infections show up as clinical mastitis.
Some cows exhibit elevated somatic cell counts without ever showing clinical signs of mastitis.
In addition, once infections become clinical, they have a tendency to convert to subclinical infections rather than being completely cured. This particularly problem arises more frequently when using non-antibiotic mastitis treatments. Environmental streps can be a significant cause of infection in dry cows and pre-fresh heifers. Strep uberis-infected cows appear to shed high levels of bacteria in their milk. Traditionally, we think of Strep agalactia as the one strep that will significantly increase standard plate or raw counts.