Conditions or ailments that are the cause of a problem that you see - your observation.

Your vet may diagnose

Aged Maiden Mare Syndrome


This diagnosis is common in older mares of any breed that have never been bred before.

In a normal, fertile mare, the cervix is relaxed when the mare is in full estrus, both allowing the entry of semen into the uterus and allowing extra fluid, debris and inflammatory products to be expelled post-breeding. For mares having this syndrome, the cervix is abnormally closed despite the mare being in strong heat. This prevents normal uterine clearance post-breeding and predisposes the mares to inflammation and infertility.

Diagnosis is through veterinary rectal palpation, ultrasound and manual examination of the cervix.

Treatment may require dilation of the cervix using certain topical or systemic medications. These mares also often require treatment of the uterus, such as flushing and medications to help the uterus contract.

my vet's role


The prognosis is fair for successful breeding. Some of these older mares have other reproductive problems and may be difficult to breed.

my role

Questions To Ask Your Vet:
  • Is this one of the reasons that my older maiden mare is hard to breed?
  • Do you use topical treatments to help dilate the cervix & improve the situation?

Mares should ideally be bred for the first time when they are between 3-10 years old.

further reading & resources

Author: Doug Thal DVM Dipl. ABVP