Horse Side Vet Guide ®

Equine Health Resource

Persistent or Irregular Heat Behavior in Mare

Code Orange - Call Your Vet at Their First Available Office Hours

Code Yellow - Contact Your Vet at Your Convenience for an Appointment

Code Orange - Call Your Vet at Their First Available Office Hours

  • If the behavior seems extreme, or the horse seems to be in distress.

Code Yellow - Contact Your Vet at Your Convenience for an Appointment

  • If you want to rule out any physical issue being a factor in the behavior.
  • You are interested in pursuing treatment for the behavior.

In the northern Hemisphere, most mares experience estrus cycles between April and October. This season may begin earlier or end later depending on where the mare lives. During breeding season, average mares experience a 21 day heat cycle, with 15 days out of heat and 6 days in heat.

Signs that a mare is showing heat can include irritability, lack of focus, reluctance to work, sensitivity to touch, aggressive (kicking and biting), elevating the tail and opening and closing the vulvar lips (winking), and/or excessive squatting and urination. This is usually accentuated when mares are around stallions and some geldings.

Hormonal changes are believed to cause these behavioral changes. Discomfort from ovulation may also affect behavior at the end of estrus. Abnormal and irregular heat cycles or heat-related behavior can arise from a variety of problems, including ovarian abnormalities and uterine infections.

WHAT TO DO

Try to track and record the frequency and duration of the abnormal behavior, and share this information with your vet.

WHAT YOUR VET DOES

Since perceived abnormal behavior does not always coincide with a real heat cycle, your vet will need to perform a thorough exam to determine the underlying cause. This exam typically includes evaluation of the reproductive tract, and potentially hormone profiles.

Managing this problem may be very important to the mare’s future fertility and use as a riding horse.

Author: Doug Thal DVM Dipl. ABVP

CONTACT US

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

Sending