Early Fetal Loss Numbers Normal

On Jan. 25 the University of Kentucky Livestock Disease Diagnostic Center reported 77 equine abortions from Dec. 30, 2001 through Jan. 19, 2002. That number, comparable to the 75 reported over the same period in 2001, could ease fears of lingering effects of mare reproductive loss syndrome (MRLS).

One of the early indications of MRLS, which caused late-term abortion and early fetal loss in as many as 3,500 mares in Central Kentucky in 2001, was a high number of foal deaths. On May 5 of last year 73 foals/fetuses were submitted to the Diagnostic Center, and by the end of foaling season about 516 fetuses were reported.

Farm workers and mare owners have anticipated foals of 2002 with some apprehension, but as of Jan. 27, all signs point to a typical season.

"I think as far as any knowledge I have, I don't think anybody is seeing anything they wouldn't expect in a normal year," said Dr. Walter Zent, a reproductive veterinarian with Hagyard, Davidson, McGee near Lexington.

The cause of MRLS is still unknown but appears to be related to an unusual chain of weather events. Below normal temperatures and drought in March were followed by high temperatures and rapid plant growth in early April, then two days of severe frost on April 17 and 18, and finally uncommonly higher temperatures.

Theories for the cause have included mycotoxins in pastures, endophytes in grasses, cyanide from drought- and frost-damaged black cherry trees, and an abundance of Eastern tent caterpillars, which feed on the cherry tree leaves.

The University of Kentucky will hold a discussion meeting on MRLS on Feb. 4 in Lexington. Anticipated topics include monitoring plans for 2002, a clinical synopsis of MRLS, and tent caterpillar management.

About the Author

Kristin Ingwell Goode

Kristin Ingwell Goode was a staff writer for The Blood-Horse, a weekly Thoroughbred news magazine and a sister publication to The Horse.

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