A retained placenta poses serious health risks to your mare. However, with swift veterinary intervention, a successful outcome is possible. In this article, we discuss the third stage of labour — expulsion of the placenta — and the problems that may occur.
Amongst the excitement and relief that follows a smooth delivery, the third and final stage of parturition mustn’t be forgotten. During this stage, your mare remains in labour, with strong uterine contractions that continue until the placental membranes are expelled.
Normally, this process should take place within an hour following birth, resulting in expulsion of the entire placenta. However, a number of problems can occur that leave the placenta, or parts of it, retained within the uterus, including:
- Dystocia (a difficult birth)
- Endocrine imbalance
While there are other causes of a retained placenta, not all of them are yet understood. Following a difficult birth, your mare’s uterus may simply be too fatigued to continue uterine contractions — leaving part or all of the placenta retained.
At first glance, a retained placenta may not seem serious, as many mares show no outward signs. However, infection can set in rapidly as the uterus is unable to shrink and the cells of the retained placental membranes deteriorate.
Within just 12 hours, a retained placenta can lead to toxic metritis (inflammation of the uterus), which often escalates to endotoxemia and laminitis. If placental membranes are retained for more than 24 hours, the uterine wall becomes necrotic.
Checking the Placenta
Following birth, the expelled placenta should be checked thoroughly to ensure it’s intact. However, minor tears can go unnoticed. If you have any concerns during the third stage of labour, contact your veterinarian immediately.
Using a rectal examination and ultrasound, your veterinarian will be able to determine the degree of uterine shrinkage and the possibility of retained placental membranes. In cases where the placenta is visibly protruding from the vulva, diagnosis is inherently easier.
While you await your veterinarian, ensure the hanging placenta is carefully tied to prevent your mare from stepping on it while she nurses her newborn foal.
Removing the Placenta
You should never attempt to remove the placental membranes. Pulling the placenta can cause severe harm, including toxic metritis, haemorrhage and even death.
Your veterinarian is the best person to diagnose, treat and remove a retained placenta, without causing any unnecessary complications that compromise your mare’s health, wellbeing or reproductive future.