What is Retained Placenta?
In normal births, the horse’s placenta is expelled intact with no pieces left behind. However, in some cases the placenta tears and leaves behind pieces still attached to the uterus. No matter if the piece is big or small, the result will be the same: serious illness and possible death if not treated. Retained placenta leads to blood poisoning, laminitis, possible permanent disability, or even death. This is not a condition that should be taken lightly. There are multiple methods a veterinarian can utilize to expulse the retained placenta; it is not something you should attempt on your own.
Retained placenta in a horse is a medical emergency. If even the smallest amount is retained, your horse will become seriously ill and it will possibly lead to her death. Call a veterinarian immediately if you suspect a piece of the placenta is retained in the uterus.
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Symptoms of Retained Placenta in Horses
Symptoms of a retained placenta may include:
- Excessive sleeping or resting
- Colic symptoms
- Swollen and painful joints
- Inability to stand
- Hot feet
- Increased digital pulse
- Hesitant gait
- Sawhorse stance
- Pain in the toe region
Other symptoms may be uterine inflammation, peritonitis, permanent disability, and death.
Your mare can experience partial retention, or retention of the entire placenta. The partial retention is just as life-threatening as full retention. The most common part of the placenta to be retained is the area of the chorioallantois where it attached to the tip of the non-gravid horn. This section of the mare’s system has larger, more branched villi with additional placental folds causing it to be attached more securely and not as easily released.
Causes of Retained Placenta in Horses
There is no specific cause of retained placenta in horses. However, it is associated and more commonly seen in cases of infection, short or prolonged gestation, uterine atony, dystocia, cesarean section, hydrops condition, and abortion. Mares who have retained the placenta or fetal membrane previously are said to have an increased risk of recurrence.
Diagnosis of Retained Placenta in Horses
Diagnosis will be based on your mare’s symptoms and a thorough examination of the placenta after foaling. Your mare should expel the placenta 30 minutes to 3 hours after parturition. In cases of retained placenta, expulsion does not occur for 8 to 12 hours or even longer. Non-expulsion past 3 hours is considered abnormal, but once the 12th hour hits, it is considered a medical emergency.
Immediately after foaling, you and your veterinarian should examine the placenta and ensure all the parts have been expulsed entirely. As your mare is foaling, you should collect the expelled placenta and place it in a clean area to prevent tearing and contamination so that you may properly evaluate it once the foal is born. In proper parturition, the placenta is expelled inside out and intact; the chorionic surface is on the inside and the allantoic surface on the outside. By laying it out in a clean area, you can examine it for any areas or abnormalities. Any areas of discoloration, lack of villi, or tearing should be areas of concern.
Treatment of Retained Placenta in Horses
Even the smallest amount of retained placental tissue can cause a life-threatening condition in your horse. The first treatment most veterinarians start with is administration of oxytocin. This is the drug that promotes milk let down in any pregnant animal and also promotes uterine contractions and the release of microvilli from their attachments. Administration of oxytocin should begin three hours post partum if there is believed to be a part of retained placenta.
Another technique sometimes used is the Burn’s technique. If the chorioallantois is intact, the veterinarian distends it by filling it with a weak solution of povidone-iodine mixture in water. The fluid is held in the uterus for a few minutes before letting the horse expulse it. Studies believe this re-distention causes endogenous oxytocin to be released and the fluid filled membrane is then expelled intact.
Some people attempt to remove the placenta manually from the mare if freely hanging from her vulva. However, extreme caution needs to be taken if doing this method. You scrub and lubricate your arm and hand and carefully insert it into the mare. You place your hand between the placenta and uterine wall and slowly peel the placenta away. Trying to keep it in one piece is ideal. However, consulting a trained equine veterinarian is the best protocol.
Recovery of Retained Placenta in Horses
Retained placenta in horses is a serious condition. If all parts of the placenta were successfully removed in a short time after parturition, your mare should not experience any long term side effects. However, if she began to develop clinical symptoms of any sort, you will need to treat those in addition to placental removal. The longer the placenta is retained, the more serious her condition will become and her prognosis will decline. In some cases, there can be long term side effects from the secondary conditions the retained placenta led to, or it could even cause death. This is not a condition you should handle on your own. Call a veterinarian when your mare begins to foal to ensure everything goes as well as possible.