Common and Uncommon Ovarian Abnormalities

Knowing which ovarian abnormalities are benign and which are pathogenic can help vets manage mare successfully.

No account yet? Register


Common and Uncommon Ovarian Abnormalities
About 85% of anovulatory follicles luteinize and 15% remain as persistent anovulatory follicles. | Photo: Courtesy Dr. Patrick McCue

Veterinarians see a wide variety of ovarian abnormalities when evaluating broodmare reproductive tracts. Knowing what’s benign and what’s pathogenic–causing disease or damage–can help them best manage these mares.

At the 2017 American Association of Equine Practitioners convention, held Nov. 17-21 in San Antonio, Texas, Patrick McCue, DVM, PhD, Dipl. ACT, reviewed common and uncommon ovarian issues that veterinarians might encounter when performing transrectal ultrasound exams. McCue is the Iron Rose Ranch Chair in Equine Reproduction at Colorado State University’s Equine Reproduction Laboratory.

Common Ovarian Problems

Anovulatory follicles “Approximately 4% to 8% of large dominant follicles (those faster-growing that are next-up for ovulating) in a mare in estrus fail to ovulate,” said McCue. Of these anovulatory follicles, about 85% luteinize (transform into a structure that produces progesterone–the pregnancy-maintaining hormone) and 15% remain as persistent anovulatory follicles

Create a free account with to view this content. is home to thousands of free articles about horse health care. In order to access some of our exclusive free content, you must be signed into

Start your free account today!

Already have an account?
and continue reading.


Written by:

Alexandra Beckstett, a native of Houston, Texas, is a lifelong horse owner who has shown successfully on the national hunter/jumper circuit and dabbled in hunter breeding. After graduating from Duke University, she joined Blood-Horse Publications as assistant editor of its book division, Eclipse Press, before joining The Horse. She was the managing editor of The Horse for nearly 14 years and is now editorial director of EquiManagement and My New Horse, sister publications of The Horse.

Related Articles

Stay on top of the most recent Horse Health news with

FREE weekly newsletters from

Sponsored Content

Weekly Poll

sponsored by:

What do you think: Can pituitary pars intermedia dysfunction (PPID) be managed by medication alone?
153 votes · 153 answers

Readers’ Most Popular

Sign In

Don’t have an account? Register for a FREE account here.

Need to update your account?

You need to be logged in to fill out this form

Create a free account with!