Mastitis continues to be one of the most costly problems in many dairy farms. Mastitis can manifest itself in either clinical or subclinical form. Clinical mastitis is when milk appears abnormal (the presence of flakes, clots, strings or if it is watery). The mammary gland also may be warm or hard to the touch and may exhibit increased sensitivity. In severe cases, systemic signs may be apparent, such as fever, cow off feed or in shock. Subclinical mastitis occurs when both milk and mammary gland appear normal but somatic cell counts (SCC) are elevated to a level above 200,000 cells per mL.