Manual Reduction of Twins in Mares (AAEP 2010)

While a mare with twins by her side is rare and sometimes celebrated, twinning in horses is actually dangerous for the mare, especially during delivery. More often than not, one of the twins, generally the smaller and weaker of the two, will die before birth. In fact, the chances of a mare carrying twins to term and delivering them successfully are about one in 10,000. The manual reduction of one
Share
Favorite
Close

No account yet? Register

ADVERTISEMENT

While a mare with twins by her side is rare and sometimes celebrated, twinning in horses is actually dangerous for the mare, especially during delivery. More often than not, one of the twins, generally the smaller and weaker of the two, will die before birth. In fact, the chances of a mare carrying twins to term and delivering them successfully are about one in 10,000.

The manual reduction of one embryo in mares in the very early stages of carrying twins is a practice that was introduced to the breeding community in 2006 (the technique was first described in the '80s along with the increased use of the ultrasound to detect twin pregnancies), and since then it has become a common practice in managing twin cases. In a presentation given at the 2010 American Association of Equine Practitioners convention, held Dec. 4-8 in Baltimore, Md., Pete C. Sheerin, DVM, Dipl. ACT, reviewed a study he conducted on manual twin reduction. Sheerin, a reproduction specialist who carried out his study at Rood & Riddle Equine Hospital, in Lexington, Ky., examined whether the performance of the veterinarian, the drug treatment used, or the mare's age impacted the procedure's success rate.

In his retrospective approach Sheerin used the medical records of mares that underwent twin reduction at Rood & Riddle. The procedures were performed between Days 13 and 20 of gestation. Sheerin explained that mares from the same farms that had only one embryo served as controls in the study. He noted the mares' ages (which ranged from 3 to 24 years), the veterinarian that performed the procedure (14 veterinarians total), and the combination of drugs that were used on the mares (22 combinations).

Sheerin said that the mares that had undergone a twin reduction treatment had a marginally lower live foal rate (80.3%) than those mares that carried a single foal since the beginning of their pregnancy (86.7%). There was no difference in the live foal percentage of the mares that underwent a reduction from Day 13 to 16 of gestation than those undergoing the procedure between Day 17 and 20

Create a free account with TheHorse.com to view this content.

TheHorse.com 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 TheHorse.com.

Start your free account today!

Already have an account?
and continue reading.

Share

Written by:

Erica Larson, former news editor for The Horse, holds a degree in journalism with an external specialty in equine science from Michigan State University in East Lansing. A Massachusetts native, she grew up in the saddle and has dabbled in a variety of disciplines including foxhunting, saddle seat, and mounted games. Currently, Erica competes in eventing with her OTTB, Dorado.

Related Articles

Stay on top of the most recent Horse Health news with

FREE weekly newsletters from TheHorse.com

Sponsored Content

Weekly Poll

sponsored by:

Where do you primarily feed your horse?
279 votes · 279 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 TheHorse.com!