Postpartum endometritis in dairy cows: current status of diagnosis, therapy and prevention

Abstract

Clinical (CE) and subclinical endometritis (SCE) occur a few or several weeks postpartum in dairy cows. Immunosuppression, microbial proliferation and disruption of endometrial lining of the uterus are risk for the development of metritis which can be associated with increased likelihood of development of endometritis. Diagnostic approaches for CE have utilized the vaginoscopic presence of pus in the vaginal lumen as the common diagnostic criterion although currently Metricheck and ultrasonography are preferred procedures. The identification of pathologic numbers of microbes in the uterus appears difficult unless the samples are collected using specialized instruments. Inflammatory changes in the endometrium (of CE affected cows) can be identified with high accuracy in histologic sections of the endometrial biopsy specimens or hysteroscopy however, such approaches are limited to specialized cases only. Cows with SCE evidence a cervico-vaginal discharge without pathogenomic properties (pus and or altered consistency) and thus the diagnosis of SCE continues to be presumptive in cows with lowered fertility. Ultrasonography and uterine cytology on swabs or fluids collected from uterus have been considered accurate for the diagnosis of SCE. The diagnostic criterion in uterine cytology is the presence of higher (5–18%) polymorphonuclear leucocytes (PMNs) during 22–45 days postpartum. However there is lack of consensus in the cutoff percent of PMNs for establishing SCE in cows at different days postpartum. Therapeutic approaches for CE have suggested the systemic and intrauterine infusion of antimicrobials, IM administration of prostaglandins and chemotractant agents or antioxidants infused intrauterine. There is a lack of consensus in many studies on the usefulness of intrauterine infusion of antimicrobials and systemic prostaglandins especially in terms of overall improvement of subsequent fertility. The intrauterine infusion of chemotractant agents and antioxidants offer potential benefit over other therapies particularly for SCE. Preventive measures for endometritis include the administration of selenium and vitamin E, however peri-parturient management of cows appears to be of utmost significance. It was concluded that diagnostic approaches for CE and SCE need validation and till then presence of pus in vaginal secretions is the easiest approach for diagnosis. Therapy of CE and SCE should be weighed against the potential benefits and residue implications and the severity of the condition. Periparturient management of dairy cows appears to be the most appropriate preventive measure.