Subclinical mastitis (SCM)  is an inflammation of the mammary glands that does not cause any visible changes in the milk or udder. Milk looks normal, but  subclinical infected cows produce less milk and the quality of the milk deteriorates. Subclinical mastitis is considered the most economically important form of mastitis due to its higher prevalence and difficulty in identifying and destroying long-term effects compared to clinical mastitis. The disease is considered to be the most common disease in dairy cows around the world and is 15-40 times more common than clinical mastitis. Subclinical mastitis is a multi-pathogenic complex disease caused by potential risk factors rather than infectious pathogens and other non-communicable factors . The disease is usually unnoticed by farmers and cannot be identified without laboratory or field trials, as there are no visible signs.  The main problem with subclinical mastitis is the potential to develop into clinical mastitis, which increases the cost from discarded milk and the cost of additional treatment and veterinarians. Most casts due to intramammary infection are subclinical and an increase in somatic cell count is the only indicator of infection. Therefore, in order to avoid persistent mammary glands infections and the spread of the disease, new diagnostic tests need to be developed to detect SCM rapidly. This contributes to the success of treatment and control.