Cytologic and histologic characteristics of endometritis in postpartum dairy cows

Endometritis is a prevalent uterine infection in postpartum dairy cows that causes some alterations in the endometrium. So, the aim of this study was to determine the comparative cellular and histological characteristics of uterus, especially neutrophils index and cell morphological alterations, in healthy and endometritic Holstein cows. Thirty non-pregnant cows were used. Based on uterine discharge score, they were grouped into healthy (nine) and endometritic (twenty one) cows. Uterine discharges were sampled at day 0 of oestrus cycle for studying cellular characteristics. At second day of cycle, larger horn of uteri were sampled for histological investigations. Also, blood samples were collected at days 0, 3 and 9 for measuring of progesterone concentrations changes. Cytological study of uterine discharge showed that the bacterial and neutrophils population (P<0.01), and also cell alterations indices (P<0.05) were affected in endometritic group. Histologically, the thickness of endometrium, neutrophils infiltration, glands dispersal and percent of fibrotic regions in endometritic cows increased significantly. In addition, staining density (P<0.01) and cellular solidarity (P<0.01) in endometrial glands were decreased in endometritic cows. Also, the progesterone concentrations were in higher marginal levels during entire experimental period in affected cows. The present results indicated that uterine cytology and endometrial biopsy in postpartum dairy cows might be useful and accurate procedures for detecting existence and severity of endometritis.