Horse Side Vet Guide ®

Equine Health Resource

Vaginal or Vulvar Discharge (Clear or Mucous) Non-Pregnant Mare

Code Green - Contact Your Vet to Obtain Useful Advice & Resources

Code Green - Contact Your Vet to Obtain Useful Advice & Resources

  • If you have other questions or concerns about the horse.

A clear thick mucous discharge is normal for mares in heat. When this discharge becomes crusted with dirt and debris, it can make the mare look “dirty.”


Assess the horse’s general health using the Whole Horse Exam (WHE), paying particular attention to rectal temperature and the color and consistency of any discharge.

Keep track of your mare’s heat cycles. Normal clear discharge should cease after estrus (5-7 days total). If you are breeding your mare, your vet should examine her for pregnancy at 14-16 days after breeding.

Assess the discharge. If the discharge is opaque white or yellow there is greater reason to call your vet because this could indicate a uterine infection, which can cause a variety of problems and should be detected and treated appropriately. Share your findings and concerns with your vet.


Your vet will try to determine whether the vaginal discharge is within normal limits. We do this through assessment of the discharge, and examination of the reproductive tract with rectal palpation and ultrasound. They might also assess uterine health using cytology, culture and possibly biopsy.

Author: Doug Thal DVM Dipl. ABVP


We're not around right now. But you can send us an email and we'll get back to you, asap.