Florida vet downplays deaths

Animal pathologists in Florida have confirmed that two recent foal deaths and one late-term abortion in the state were consistent with the medical phenomenon known as mare reproductive loss syndrome, a veterinarian at the University of Florida's Veterinary College of Medicine said Monday.

The abortion came to the attention of pathologists this weekend, according to the veterinarian, Dr. Dana Zimmel, and it was quickly diagnosed as being consistent with the syndrome, known as MRLS. The abortion occurred on March 13, Zimmel said.

Four cases in Florida this year - two abortions and two foal deaths - have been linked to MRLS, which is thought to be caused by the inadvertent consumption of Eastern tent caterpillars by pregnant mares.

The cases have renewed fears that the syndrome has become resurgent in the horse community. An outbreak in 2002 in central Kentucky caused approximately 30 percent of mares to have late-term abortions.

Zimmel said, however, that fears about an outbreak in central Florida are likely overblown. She noted that researchers had no way to diagnose the syndrome until the Kentucky outbreak was studied.

"Overall, there hasn't been an increase in fatalities compared to other years," Zimmel said. "This was probably a subtle cause of abortion for a long time, but we didn't have the tools to say what it was from. And so I think it's important for people to realize that we're not looking at an outbreak. It's probably run its course."

Last week, the Florida Thoroughbred Owners and Breeders Association issued a health advisory asking horse breeders to check their pastures for caterpillars and remove any mares from locations where the caterpillars lived. The caterpillars are known to favor apple, crabapple, and cherry trees.