Effect of Escherichia coli endotoxin-mediated inflammation of one mammary quarter of the bovine udder on diapedesis into other quarters.

Implantation of 1 microgram Escherichia coli endotoxin into one papillary duct of a bovine udder frequently resulted in a mild inflammatory process in the treated quarter which was measured by use of the Wisconsin mastitis test (WMT) on quarter fore milk samples. Inflammation of a fore quarter was usually (18/24) accompanied by a transient elevation in WMT score from the homolateral hind quarter, but rarely (1/25) from the contralateral quarter. Inflammation in a hind quarter rarely (2/26) affected the homolateral fore quarter and never (0/25) the contralateral quarter. The pattern of responses suggests tha absorption and initial removal of endotoxin from the mammary gland occurs via the lymphatic rather than the blood system.