Here are some of the most common causes:
1. Uterine Inertia: This is the most common cause of postpartum hemorrhage in mares. It occurs when the uterus doesn't contract properly after the foal is born, leading to excessive bleeding. This can be caused by:
* Weak uterine muscle: A mare's uterine muscle may be weakened by factors like age, previous uterine problems, or poor nutrition.
* Uterine infection: Infections can weaken the uterus and make it difficult for it to contract.
* Retained placenta: If the placenta doesn't detach and expel naturally, it can obstruct the uterus and prevent it from contracting.
* Overstretching of the uterus: Having multiple foals or a very large foal can overstretch the uterus and hinder its ability to contract.
2. Uterine Rupture: A tear in the uterus can occur during labor, especially if the foal is too large or there are complications with the birth. This is a life-threatening emergency.
3. Uterine Inversion: This is a rare condition where the uterus turns inside out. It can happen during labor or immediately after birth and is a very serious condition.
4. Cervical Laceration: A tear in the cervix can happen during labor, especially if the foal is large or the birth is difficult.
5. Hemorrhage from other areas: While less common, bleeding can occur from the vagina, vulva, or other areas. This may be caused by trauma during birth or other underlying conditions.
What to do if you suspect a mare is hemorrhaging:
* Call your veterinarian immediately.
* Keep the mare calm and quiet.
* If possible, monitor vital signs like pulse and respiration.
* Be prepared to provide the veterinarian with information about the mare's health history, the birth, and any potential complications.
Remember: Postpartum hemorrhage is a life-threatening situation. Prompt veterinary intervention is critical for the mare's survival.