http://www.vny.com/cf/News/upidetail.cfm?QID=186330

Wednesday, 16 May 2001 17:29 (ET)

USDA vets join fetal loss investigation

LEXINGTON, Ky., May 16 (UPI) -- University of Kentucky scientists trying to determine why so many mares lost foals this season asked the Department of Agriculture Wednesday to assign three USDA veterinarians to the investigation.

The scientists said they are fairly certain what has been dubbed mare reproductive loss syndrome is not contagious or infectious and are concentrating their efforts on various toxins that may have developed in pastures.

There have been an unusually high number of late-term miscarriages and stillbirths, as well as foals being born weak and dying just a few days later. There also have been a high number of so-called "red-bag" births, where the placenta is delivered before the foal, which is deprived of oxygen, contributing to the weakness. A second problem is the number of foals apparently dying in utero.

Horse breeders have sent 477 aborted and stillborn fetuses to the Gluck Equine Research Center for examination since April 28. Necropsies have shown evidence of problems with the lungs, eyes and fluid retention.

One of the areas being investigated is whether this year's unusual winter weather could be responsible -- warm and dry early on, followed by a hard freeze, setting the stage for development of fungus or toxin in field grasses eaten by horses. Pasture management specialists also note an unusually higher number of disease-carrying caterpillars this year.

The scientists said they will conduct an epidemiological survey that will look at such issues as mowing patterns, fertilization patterns, pasture management procedures, pasture composition and horse management procedures.

The scientists are trying to determine if ergot alkaloids produced by fungi, several mycotoxins, phyto estrogens and/or other compounds in pasture grasses are responsible for the syndrome, which has killed about 20 percent of the expected foals this spring. At some farms, losses have been as high as 70 percent.

A survey last week indicated 678 abortions on 122 farms across Kentucky as of May 7. Since then, many more mares have either aborted or been found no longer pregnant.

In recent days, veterinarians have reported older horses suffering inflamed, cloudy eyes, fever, inflamed hooves and heart conditions in unexpected numbers, but it is unclear whether these conditions are related to the foaling problems.

"It's certainly tempting to think they're related because they're occurring at the same time," Dr. Claire Latimer told the Louisville Courier-Journal. "It's a true cardiac epidemic, if you will," Dr. Doug Byars, an internal medicine specialist at Hagyard-Davidson-McGee Clinic, told the Lexington Herald-Leader.

"I think our biggest problem at this stage is trying to segregate the toxic insults from the normal things that run through horses. I think we've got everybody's sonars out right now."

Latimer, a veterinary ophthalmologist, said she had seen 14 cases of eye problems leading to blindness in the past two weeks. The norm is one case a season.

The researchers have recommended limiting exposure to grass. The Thoroughbred industry estimates losses at $225 million so far this year. Kentucky has 550 Thoroughbred breeding farms that produce 10,000 foals a year. Stud fees, ranging from $20,000 to $400,000 on average, generally are paid only after the birth of a healthy foal.

Some breeders say the situation is similar to the springs of 1980 and 1981, when the cause for numerous foal losses was never determined. Copyright 2001 by United Press International. All rights reserved.

-- Swissrose (cellier3@mindspring.com), May 16, 2001