Hormonal imbalances, such as low levels of oxytocin or excessive progesterone, can interfere with uterine contractions necessary for placental expulsion (see the attached image – attributed by linking – for reference). Infections and inflammations, such as metritis or endometritis, can cause uterine inflammation and prevent the placenta from detaching. Additionally, nutritional deficiencies, particularly those of selenium, vitamin E, or zinc, can weaken the attachment between the placenta and the uterine lining.
- Placental Adhesions: Adhesions between the placenta and the uterine wall can hinder the natural expulsion process, causing retention.
- Uterine Infections: Infections of the uterus, such as metritis, endometritis, or pyometra, can weaken the cow’s ability to expel the placenta.
- Dystocia or Difficult Calving: When a cow experiences a challenging birth, with prolonged labor or abnormal presentation, the risk of retained placenta increases.
- Nutritional Imbalances: Poor nutrition, particularly during late pregnancy, can weaken the cow’s immune system and make her more susceptible to reproductive complications, including retained placenta.
- Hormonal Imbalances: Hormonal imbalances, such as low levels of progesterone, can disrupt the normal processes of placental detachment and expulsion.
- Diseases: Diseases like brucellosis, leptospirosis, bovine viral diarrhoea and infectious bovine rhinotracheitis can cause retained afterbirth in cows.
- Body Condition Score: Over conditioning (high BCS) or under conditioning (low BCS) can lead to retained placenta after calving.
- Environmental Factors: Exposure to unsanitary or stressful environments, extreme weather conditions, or inadequate ventilation can contribute to the development of retained placenta.
- Metabolic Disorders: Cows with metabolic disorders like hypocalcemia (milk fever) or ketosis have an increased risk of experiencing retained placenta.
- Medications or Treatments: Certain medications or treatments, including hormonal interventions or improper use of oxytocin, can interfere with the natural detachment and expulsion of the placenta.
Preventive Measures