The efficacy of intramuscularly and intramammarily administered
cefquinome was evaluated in experimental Escherichia coli
mastitis in dairy cows. Forty-seven multiparous, Israeli Holstein cows in early lactation that produced at least 25 L/d of milk were used, and 400 to 750 cfu of E. coli were infused into two healthy quarters of each cow. Cows were randomly assigned to one of the following treatment groups: 1) 75 mg of
cefquinome administered intramammarily three times at 12-h intervals, 2) 75 mg of
cefquinome administered intramammarily three times at 12-h intervals and 1 mg/kg of
cefquinome administered intramuscularly two times at a 24-h interval, 3) 1 mg/kg of
cefquinome administered intramuscularly two times at a 24-h interval, and 4) 75 mg of
ampicillin and 200 mg of
cloxacillin administered intramammarily three times at 12-h intervals. All cows developed typical signs of acute clinical
mastitis by 12 to 16 h postinoculation. Parenteral
cefquinome therapy, with or without intramammary
cefquinome (groups 2 and 3), significantly improved clinical recovery and return to milk production. The bacteriological cure rates were considerably and significantly higher for cows in the groups treated with
cefquinome than for cows in the group treated with
ampicillin and
cloxacillin. This study supported the efficacy of
cefquinome in the treatment of clinical coliform
mastitis in dairy cows.