Caterpillar Blacmed for Kentucy Horse Deaths

[Dori Sosensky]

Thought this might be of interest.


                                          Caterpillar Blamed for Kentucky 
Horse Deaths
                                          Reuters
                                          May 25 2001 1:01PM

                                          LEXINGTON, Ky. (Reuters) - The 
illness that caused hundreds of
                                          Kentucky mares to miscarry or 
deliver stillborn foals has been traced to
                                          caterpillars which had eaten 
cherry tree leaves tainted with naturally
                                          occurring cyanide, officials said 
on Friday.

                                          Unusually high levels of the 
poison in populous black cherry trees was
                                          somehow transferred to the mares 
-- possibly through feces from
                                          Eastern tent caterpillars in 
bluegrass pastures -- and killed the unborn
                                          horses in the womb.

                                          Roughly one out of 20 foals due 
to be born this spring died, and next
                                          year's foal crop may be cut 
sharply, causing at least $225 million in lost
                                          foal sales and stud fees in 
Kentucky's $1 billion annual horse industry.

                                          "Mare reproductive loss 
syndrome," the name given to the illness that
                                          peaked earlier this month, has 
subsided recently, veterinarians said.

                                          Breeders had taken desperate 
measures such as delivering foals early
                                          and keeping mares out of their 
famed bluegrass pastures. Originally,
                                          scientists had thought 
toxin-producing molds had attacked pastures,
                                          which in turn had caused the 
reproductive problem in the mares.

                                          But scientists told breeders on 
Thursday that the cause of the foal deaths
                                          was likely the caterpillar and 
the cyanide-producing trees, and that the
                                          problem was safely past.

                                          In future, horse breeders could 
take precautions when caterpillar
                                          populations are heavy, such as 
restricting grazing, University of Kentucky
                                          Agriculture Department spokesman 
Haven Miller said in a telephone
                                          interview.

                                          "The unusual weather pattern 
could have caused the cyanide levels in the
                                          trees to be higher," Miller said. 
"We had a similar problem in 1980-81,"
                                          when many unexplained horse 
deaths occurred.

                                          This spring featured similarly 
warm, dry weather followed by a sudden
                                          frost, which not only damaged 
pastures but may have increased the
                                          poison content in the trees. 
Breeders have known about the cyanide
                                          content in cherry trees, and some 
chop them down.

                                          Agronomists had reported a heavy 
infestation of Eastern tent caterpillars
                                          this spring, which spread webbing 
in the branches and can defoliate
                                          trees.

                                          "If confirmed, this working 
hypothesis would lead to a very positive outlook
                                          for prediction and prevention of 
recurrence of mare reproductive loss
                                          syndrome," Scott Smith, dean of 
the University of Kentucky's College of
                                          Agriculture, told the breeders.


Dori

Dori Sosensky
New Haven, CT

Dori.Sosensky at Yale.Edu