In addition to the experimentally induced mastitis, the mammary secretions from the glands of cattle with spontaneous Staphylococcus aureus dry-period mastitis displayed milk clot formations and significant increases in their levels of PMNL counts, elastase, LDP, and IL-8, compared with those of the mammary secretions from the uninfected glands. Here, CXCL8 is linked to mastitis.