Effect of uterine lavage on neutrophil counts in postpartum dairy cows

Subclinical endometritis affects approximately 30% of lactating dairy cows, causing significant economic losses to the dairy industry. Yet, there is no efficient treatment available for this condition. The present study examines the effect of uterine lavage in clinically normal cows with sterile saline solution at 30 days in milk (DIM) on the percentage of polymorphonuclear cells (PMNs) detected with endometrial cytology as an indicator of subclinical endometritis.It was hypothesized uterine lavage would be a technique to reduce the number of PMNs in the uterus, and hence be beneficial for cows affected by subclinical endometritis. Cytology samples were taken by low-volume flushing from 50 Holstein Friesian cows on 30 and 40 DIM. On Day 30, cows were clinically examined and randomly assigned into a treatment and control group. In the treatment group, the cytology sampling on Day 30 was immediately followed by uterine lavage with 500–600 mL of sterile physiological saline (35–40 °C). Cytology sampling was repeated in all cows at 40 DIM. Lactation numbers >2, peripheral progesterone concentrations >1 ng/mL and uterine lavage at 30 DIM all were significantly associated with lesser PMN percentages at 40 DIM (P = 0.0041; 0.0187 and 0.0043, respectively). Uterine lavage might, therefore, be a useful and practical method to decrease the number of PMNs in the uterus of cattle. Results from the current study can be used as preliminary data for designing in depth therapeutic protocols for treatment of subclinical endometritis in cattle.