Association between postpartum pyrexia and uterine bacterial infection in dairy cattle.

The temperature of 90 dairy cattle was recorded for the first 10 days after parturition and the animals were categorised as either normal (< 39.7 degreesC) or pyrexic. Swabs were collected from the uterine lumen seven, 14, 21 and 28 days after parturition for aerobic and anaerobic culture; bacteria were identified and their growth was scored semiquantitatively. Blood samples were collected three times a week for the estimation of the concentrations of acute phase proteins. The cows' temperatures were often above the accepted normal range, but it was not a good indicator of the number of bacteria in the uterus. However, pyrexia was correlated with the presence of specific uterine pathogens (P < 0.05) and in particular with Prevotella species (P < 0.01). The pyrexic animals had a higher plasma concentration of the acute phase protein (alpha1-acid glycoprotein (P < 0.05). Although pyrexia is an indicator of postpartum inflammation, additional clinical signs are necessary to identify uterine bacterial infection.