From my vet textbook...
"Management practices are probably important in respect to the prevalence and type of coliform mastitis that occurs. The ability of sawdust to harbor large numbers of Klebsiella organisms has been associated with a high incidence of Klebsiella mastitis. By replacing the sawdust with sand, a dramatic reduction in Klebsiella mastitis was achieved. Sawdust bedding is not essential for outbreaks of Klebsiella mastitis, however, because these infections have also occurred in cows kept on pasture. In these cases Klebsiella organsims apparently accumulated on teat cup inflations or liners inadequately sanitized between milkings. This has also been observed in infections caused by E coli."
"Coliform mastitis is not highly contagious. Sudden outbreaks of this mastitis are not due to the appearance of a particularly virulent strain, but rather to conditions that promote increased exposure to the types of coliform bacteria in the environment, including milking equipment and bedding."
"There is good evidence that the incidence of coliform mastitis is related to the number of organisms from the environment that contaminate the teat end. ... In another experiment, dipping the teats in a culture of E coli resulted in increased infection rates, but it made no difference whether the teats were dipped before or after milking or whether the exposure involved spraying the udder during milking."
Looks like it can be environmental or transferred by milking equipment. Hope that helps, J! ;-)
And btw, for the rest of those reading this thread... ecoli IS curable, and it ain't near as hard as curing a staph cow.
