Published online by Cambridge University Press: 01 June 2009
Infections of the bovine mammary gland are considered to be ascending infections through the teat canal (Forbes & Hebert, 1968). With respect to skin and wound infections, staphylococci in particular adhere to and colonize traumatized areas (Mertz et al. 1987). Staphylococcus aureus and coagulase-negative staphylococci can colonize the teat canal for weeks before they invade upper parts of the mammary gland (Forbes & Hebert, 1968). Such teat canal infections predispose the mammary gland to mastitic infections, particularly with the so-called ‘contagious’ mastitis pathogens, namely Staph. aureus, Streptococcus agalactiae and Str. dysgalactiae.