An Arabian mare in Marion County aborted a 310-day gestation (the foal was born dead) on March 13 that was confirmed as having mare reproductive loss syndrome (MRLS), according to Dana Zimmel, DVM, Dipl. ACVIM, Dipl. ABVP, of the University of Florida’s College of Veterinary Medicine.

The first case was a Thoroughbred foal from the University of Florida research herd born on March 18 that died on March 20. The second case was a Quarter Horse foal born on March 25 that died on March 26 on a private farm. Both mares foaled in Alachua County, and both foals were born alive, were hospitalized, but were euthanatized due to their deteriorating conditions.

Zimmel said there is still one suspect case that was a late-term abortion from a Thoroughbred mare from the University of Florida breeding herd. The University of Florida herd of research mares lives near Ocala, Fla., (in Marion County) until about 30 days prior to foaling, when they are brought to the university’s farm in Alachua County. Eastern tent caterpillars (ETC), which have been linked to MRLS, were reported in fields with the dams of the first two foals; no report was available for the third foal.

No reports of early fetal losses have been reported in Florida.

University of Florida pathologist John Roberts, DVM, Dipl. ACVP, who is performing pathology on the foals, performed necropsies at the University of Kentucky’s Livestock Disease Diagnostic Center during the 2001-2002 MRLS outbreak.

An informational meeting will be held on Thursday, April 6, at the Ocala Breeders Sales facility at noon. Veterinarians and horse owners are invited to attend.

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