Mastitis is an infectious disease resulting in an inflammatory reaction in the mammary gland of the cow. The pathogens that cause mastitis include bacteria such as; Staphylococcus aureus, coagulase-negative staphylococcus, Streptococcus uberis, Streptococcus dyslactiae, Streptococcus agalactiae, enterococci and coliform bacteria including Escherichia coli and Mycoplasmas. A cow can be infected by either acquiring the bacteria from the environment or through the transmission of contagious bacteria from cow to cow during the milking process. This disease has a clearly visible clinical form with inflammation and affected milk and a sub-clinical form, where the cow does not show any visible signs of infection on the udder or abnormalities in the milk.