Streptococcus uberis. (Strep uberis)

Strep uberis mastitis is probably the most important organism with regard to mastitis in the modern dairy cow. It is an environmental organism (Control of environmental mastitis) that lives in faeces, the rumen and in all areas where there is cow contact. Whilst it is an easy organism to kill in a petri dish it is very difficult to eradicate from an infected udder. The organism may progress from being an environmental cause of infection to a contagious cause by becoming cow-adapted (Control of contagious mastitis). In other words the organism lives in the udder and transmits to other cows during the milking process in the same way as S.aureus. Large clinical outbreaks of strep uberis can result in high and fluctuating bactoscans as well as raised herd SCC.

Treatment of Strep uberis mastitis must be aggressive and targeted with specific treatment protocols. If treatment is not aggressive then there is more likelihood of cow-adapted infections developing. This is why many farms fail in their attempts to control and treat strep uberis mastitis.