The Mastitis Revolution New Approches to an Old Problem

Mastitis, an inflammatory reaction of the mammary gland that is usually caused by a microbial infection, is recognized as the most costly disease in dairy cattle. Decreased milk production accounts for approximately 70% of the total cost of mastitis. Mammary tissue damage reduces the number and activity of epithelial cells and consequently contributes to decreased milk production. Mammary tissue damage has been shown to be induced by either apoptosis or necrosis. These 2 distinct types of cell death can be distinguished by morphological, biochemical, and molecular changes in dying cells. Both bacterial factors and host immune reactions contribute to epithelial tissue damage. During infection of the mammary glands, the tissue damage can initially becaused by bacteria and their products. Certain bacteria produce toxins that destroy cell membranes and damage milk-producing tissue, whereas other bacteria are able to invade and multiply with in the bovinemammary epithelial cells before causing cell death. The current review focuses on the main pathogens that cause this inflammation and their prevalence as well as strategies to prevent their proliferation. We discuss economic loss, with the goal of demonstrating that prevention is always better than disease management.