Bovine Retained Placenta and Metritis-Pyometra Complex – NAVLE Study Guide

Overview and Clinical Importance

Retained fetal membranes (RFM) and the metritis-pyometra complex represent a continuum of postpartum uterine disorders that significantly impact dairy cattle health, welfare, and reproductive efficiency. These conditions are interconnected, with retained placenta being a major predisposing factor for subsequent uterine infections. Understanding the pathophysiology, risk factors, clinical presentations, and treatment protocols is essential for the NAVLE examination and clinical practice.

The metritis complex encompasses retained fetal membranes, metritis, endometritis, and pyometra. These diseases share common causes, often progress sequentially, and have overlapping treatment strategies. This study guide provides a comprehensive review of the pathophysiology, clinical signs, diagnosis, and evidence-based treatment approaches for each condition.

Normal Placental Anatomy and Physiology

Bovine Placental Structure

Cattle possess a cotyledonary epitheliochorial placenta, which is characterized by discrete attachment sites called placentomes. Each placentome consists of a fetal cotyledon interdigitating with a maternal caruncle. The bovine uterus contains approximately 70-120 caruncles arranged in four rows along each uterine horn. The villi of the fetal cotyledons interdigitate with the crypts in the maternal caruncles, and collagen links the interface together at multiple sites.