Bacterial contamination of the uterus in cows with various clinical types of metritis and endometritis and use of hydrogen peroxide for intrauterine treatment

The relationship of various clinical forms of uterine inflammation to bacterial contamination and the applicability of hydrogen peroxide for intrauterine treatment of clinical endometritis was the subject of this trial. Uterine contamination was compared among groups of cows according to clinical findings on days 10 ± 3 (mild or severe puerperal metritis and controls without symptoms of the disease: MM, n = 16 or SM, n = 8 and CM, n = 13) and 25 ± 3 (mild or severe clinical endometritis and controls without symptoms of the disease: ME, n = 28 or SE, n = 40 and CE, n = 10). The applicability of 3% hydrogen peroxide was evaluated on the basis of macroscopic examination of intact and closed uteri from slaughtered cows after infusion of 50, 80, and 100 ml of the solution, clinical as well as bacteriological examination of uteri in cows suffering from clinical endometritis (Group E1 - treatment for the first time, n = 18 and Group E2 - previous treatment for retained placenta or puerperal metritis, n = 12) before and seven days after intrauterine administration of 80 ml of the solution as well as subsequent reproductive performance of treated cows in comparison with untreated controls without symptoms of the disease (Group C, n = 20). A wider bacterial spectrum was found in the cows on day 10 ± 3 compared to day 25 ± 3. Arcanobacterium pyogenes was the main uterine contaminant in cows suffering from all clinical types of uterine inflammation while this bacterium was not shown to be present in any of the control cows (MM 7/16 and SM 6/8 vs. CM 0/13, P < 0.05 and P < 0.01; ME 14/28 and SE 18/40 vs. CE 0/10, P < 0.05). No macroscopic changes in uteri were found after infusion of various volumes of 3% hydrogen peroxide, only gas infiltration to the surrounding tissue occurred in completely closed uteri after deposition of 100 ml of the solution. Clinical symptoms of endometritis disappeared in 83% (E1) and 67% (E2) of affected cows and bacterial contamination decreased markedly (but not significantly) in both groups up to day 7 after intrauterine treatment. Reproductive parameters in treated cows compared to controls were not different. The results show an important role of A. pyogenes in the etiopathogenesis of all clinical forms of uterine inflammations in postpartum cows and support the use of 3% hydrogen peroxide for intrauterine treatment of clinical endometritis even though sufficient antibacterial effects of the treatment are still to be confirmed.