than in unaffected cows (Querenga¨sser et al., 1999).
It may be hypothesized that the affected quarter is
responsible for the increased composite SCC, as the
SCC of the remaining teats was normal and did not
change significantly throughout the study period. Teat
injuries seem to increase the risk of quarter infection
over a long period of time (Tscha¨ppa¨t et al., 1976; Agger
and Willeberg, 1986). Further study is needed to determine
if pathogens from the affected quarter can infect
the unaffected quarters. Because the odds of detecting
pathogens were low in unaffected quarters and did not
change throughout the study period, it may be hypothesized
that the risk of infection is generally low. Our
results agree with others (Gedek et al., 1987), in that
esculin-positive and -negative Streptococci were most
frequently found in the milk from teats with milk
flow disorders