University of Kentucky Diagnostic Lab Seeking Answers About Foal Loss

By Kimberly L. Graetz
Lenn Harrison, VMD, Dipl. ACVP, director of the University of Kentucky's Livestock Disease Diagnostic Laboratory in Lexington, and his staff have been working long hours conducting necropsies and running tests in an attempt to find answers to the questions raised during the ongoing losses of fetuses and foals in the state. While there hasn't been time yet to compile official numbers of incoming horses for testing, more than 60 have come on some days. The normal number of incoming abortions per day at this time of year is five to six, with a little higher number per day of dead foals.

Harrison noted that this problem is not limited to Thoroughbreds. Many breeds have been seen at the Diagnostic Lab, including Appaloosas, paints, and Quarter Horses. Many breeds other than Thoroughbred don't do ultrasound exams after a mare has been pronounced in foal, so it is possible that there are early embryonic losses in other breeds that aren't being detected because mares are not being scanned.

No one yet knows the cause of these excessive numbers of late-term abortions, stillbirths, and weak foals, or of the early embryonic losses. No one yet knows whether the two problems are connected. However, Harrison agreed that it looks to be a "significant" problem and that the two syndromes probably are caused by the same thing. He said he is "keeping an open mind" about the possible causes.

The diagnostic lab personnel are stockpiling samples for more extensive testing at a later date. The good news at this point is that the problem doesn't seem to be infectious or contagious.