NATURALLY-OCCURRING ACUTE COLIFORM MASTITIS IN HOLSTEIN CATTLE

Physical examination and clinicopathologic findings from 44 adult Hols tein cows with naturally occurring coliform mastitis were studied. The cattle were grouped for comparison by stage of lactation and survival . Cattle within the first 4 weeks of lactation maintained higher media n mature neutrophil counts (1,200 versus 300/mu L) in peripheral blood than cattle later in lactation. Nonsurviving cows had higher median c reatinine concentration (2.5 versus 1.6 mg/dL) and anion gap (25 versu s 20 mEq/L), and lower serum protein (7.1 versus 7.6 gm/dL) and total CO2 (19.8 versus 25 mEq/L) concentrations than surviving cows (P <.05) . These findings indicate that cattle with uremia and metabolic acidos is are less likely to survive the infection. Bacteriologic blood cultu res were performed on 34 of the 44 cows studied. Escherichia coli was isolated from the blood in 11 (32%) cows. Clinical presentation and cl inicopathologic data were compared in bacteremic versus nonbacteremic cows to evaluate these data as predictors of bacteremia. Bacteremic co ws were sick longer prior to admission (2 versus 1 days), maintained h igher median counts of total nucleated cells (6.6 versus 2.4 x 10(3) c ells/mu L), myelocytes (0.2 versus 0 X 10(3) cells/mu L), metamyelocyt es (0.5 versus 0.02 X 10(3) cells/mu L), band neutrophils (0.7 versus 0.1 X 10(3) cells/mu L), and lymphocytes (2.1 versus 1.4 x 10(3) cells /mu L) than nonbacteremic cows, and had higher plasma fibrinogen conce ntration (600 versus 500 mg/dL) (P <.05). There were no differences be tween the physical or serum biochemical measurements. Four of 11 bacte remic cows and 5 of 23 nonbacteremic cows died or were euthanized (P > .05). The high prevalence of bacteremia seen in cows with coliform mas titis has not been reported previously, and may have been due to the d uration of disease, severity of signs, or culture technique, These fin dings suggest that systemic antibiotic therapy may be beneficial in so me severe cases of coliform mastitis. Copyright (C) 1996 by the Americ an College of Veterinary Internal Medicine.