Dr. M. K. JhalaBEENU JAIN2017-05-042017-05-042011http://krishikosh.egranth.ac.in/handle/1/5810010541Mastitis is the most important and expensive disease of dairy industry. It results in severe economic losses from reduced milk production, treatment cost, increased labor, milk withheld following treatment and premature culling (Miller et al., 1993). This disease is characterized by physical, chemical and bacteriological changes in the milk and pathological changes in the glandular tissue of the udder. The most important changes in the milk include discoloration, presence of clots and presence of large number of leukocytes. The US National Mastitis Council estimated an overall worldwide annual loss of 2 billion dollar due to mastitis (Anonymous, 2005). The annual economic losses due to mastitis in India have been estimated to be 7165 crores (Basal and Gupta, 2010). Generally mastitis occurs in two forms i.e., clinical orenVeterinary MicrobiologyStudyThesis