What was the hottest news in equine veterinary medicine in 2009? During the popular Kester News Hour session at the annual American Association of Equine Practitioners (AAEP) Convention, three top veterinarians (who focus on equine reproduction, internal medicine, and lameness/surgery) summarized the top news topics and the most significant research reports of the year for a record crowd of equine veterinarians.

The presenters during the 2009 convention, held Dec. 5-9 in Las Vegas, Nev., were:

• Scott E. Palmer, VMD, Dipl. ABVP (Equine Practice), hospital director and a staff surgeon of the New Jersey Equine Clinic in Clarksburg, N.J., and past president of the AAEP and American Board of Veterinary Practitioners;
• Margo L. Macpherson, DVM, MS, Dipl. ACT, associate professor and section chief in Reproduction at the University of Florida, and past president of the American College of Theriogenologists; and
• Bonnie R. Rush, DVM, MS, Dipl. ACVIM, professor of Equine Internal Medicine at Kansas State University, and winner of the 1996 and 2003 Carl J. Norden Distinguished Teacher Award, the 2002 Pfizer Award for Research Excellence, and the 2004 Outstanding Woman Veterinarian of the Year.

Double ovulations, hemorrhagic anovulatory follicles Investigators on one study published in the Journal of Equine Veterinary Science (JEVS) found mares were more likely to have double ovulations after receiving prostaglandin (PGF2-alpha), which is often used to manage a mare’s estrous cycle. Seventeen percent of treated mares had double ovulations compared to 3% of control mares; also, 13% of treated mares vs. only 3% of controls had one ovulatory and one hemorrhagic anovulatory follicle (HAF, which grows and fills with blood, but does not release an egg, and, thus, results in infertility for that cycle unless another follicle ovulates normally).

Researchers on another study, this one from Theriogenology, investigated the incidence of HAF formation in mares given either cloprostenol (another form of prostaglandin) or human chorionic gonadotropin, or both. They showed mares treated with cloprostenol had a slightly higher risk of HAF (8%) than mares given human chorionic gonadotropin (hCG)