Mastitis in Dairy Cows

Mastitis is the most frequent bacterial disease of adult cows and has numerous detrimental impacts on animal health and welfare, productivity, milk quality, and sustainability. Treatment of mastitis is the most common reason that antibiotics are administered to mature cattle, and prevention of mastitis requires daily attention to small management details. Mastitis occurs when intramammary infection is established by a variety of pathogens most of which are bacteria. Exposure to potential pathogens occurs through contact with organisms shed by infected cows (contagious transmission) or by contact with opportunistic organisms found in specific environmental niches. Depending on the magnitude of the inflammatory response to intramammary infection, mastitis can present in either a subclinical or clinical state. Treatment for mastitis is based on presentation and evidence-based protocols should be based on knowledge of etiology, which can be determined using a variety of diagnostic tests. While effective treatments exist, most efforts to control mastitis should focus on preventing infection by using well-defined best management practices that reduce exposure to common mastitis causing organisms.