Research Review: Anesthesia and Surgery in Pregnant Mares

If surgery requiring general anesthesia must be performed on pregnant mares, the safest time window is Days 40-220 of gestation, researchers concluded.
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Based on the research the team reviewed, Hubbell recommended that if general anesthesia must be performed on pregnant mares, the safest time window is Days 40-220 of gestation. | Photo: Thinkstock

Veterinarians and researchers know general anesthesia in horses can be risky, with reported mortality rates ranging from 0.12-1.6%. They also are well-aware that pregnancy can exacerbate those risks and possibly reduce live-foaling rates. What they’re less certain about, however, is when is the safest time during gestation to recommend elective surgeries (such as to remove masses or repair wounds).

Veterinary anesthesiologist John A.E. Hubbell, DVM, MS, Dipl. ACVAA, and colleagues at Rood & Riddle Equine Hospital in Lexington, Kentucky, recently reviewed the literature to develop recommendations on when and when not to pursue elective surgeries in mares to maintain pregnancy. He presented the team’s findings at the 2017 American Association of Equine Practitioners Convention, held Nov. 17-21 in San Antonio, Texas.

Research Says …

Hubbell first reviewed what veterinarians and researchers know about equine pregnancy, how it impacts anesthesia, and how sedation and anesthesia affect pregnancy

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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.

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