May 11, 2001 | By: Aimee D. Heald

Speaking to a crowd of horse industry professionals at Keeneland May 10, Dr. Lenn Harrison, director of UK's Disease and Diagnostic Lab said he feels strongly there is no viral component causing recent foal deaths in Kentucky's Bluegrass region.

"Overall findings certainly suggest a bacterial component," he said. "But how to interpret it in the overall picture of what has happened is something that I'm not terribly sure of. We want to look at the interactions with other agents, particularly plant toxicosis."

Harrison's lab has been deeply involved in solving the foal death mystery. From April 28 to the early hours of May 8, the lab received 318 fetuses and stillborn foals. The number received on May 8 was 28. Twenty-five more were added on May 9 and still 15 more on May 10, bringing the total to 386 as of 2 p.m. May 10.

Numbers do appear to be tapering off.

Harrison pointed out some distinct lab findings at the Keeneland meeting. Foals have been brought in representing 18 breeds, with 70 percent of the total being Thoroughbreds. The most affected area ranges from south of Lancaster, east to Morehead and areas north of Lexington as well.

"Examinations of the fetuses is being done by a professional and technical staff, who are specialists in essential disciplines of veterinary diagnostic laboratory medicine," Harrison said. "Each one of these (fetuses) is getting the benefit of work from pathologists, bacteriologists, serologists, toxicologists, and virologists as a team."

Some of the fetus' lungs are darker than usual, some foals have blood within the eyes which Harrison notes is an unusual condition. Harrison said of the 247 completed necropsies, 127 have shown strains of streptococcus species. Of the 29 aborted foals that would have born in 2002, 22 have shown streptococcus and fetal inflamation.

"Bacteria probably plays an important role in the syndrome we're dealing with, but it might not be the primary or initiating agent," Harrison said. "We feel this is not related to nitrate or nitrites."

Harrison also said copper, iron, selenium and zinc levels in mares appear to be normal so they do not believe there is a component related to those four nutritional substances.