Thursday, March 30, 2006

"MRLS"Mare Reproductive Loss Syndrome...and Caterpillers

The first documented cases of MRLS have been reported in Florida (Alachua County). For those who were living in a cave in 2001 , there was an outbreak of abortions in Kentucky that devastated the Thoroughbred industry that year, about 3000 foals were lost. There were many Veterinarians and specifically Internists that were overwhelmed with the foals and mares affected. Besides the abortions , there were foals born that soon died with pericarditis (fluid in the sack around the heart) and uveitis (inflammation in the eye). Someone who definately thinks outside the box found a link with this syndrome and the Eastern tent caterpiller(ETC).
I for one was skeptical , leaning more towards the camp looking into mycotoxins ( fungal toxins).
The ETC feeds on wild cherry and crab apple trees and are cyanide accumulators as well as potentially ergotoxins . While the actual causative agent remains ellusive, several studies have shown that feeding ETC to pregnant mares reproduces the syndrome with about a 70% abortion rate. The fact that it has now shown up in our backyard does sound an alarm. While we do a significant amount of breeding in North Florida.....Ocala must be sweating bullets about now.
The good news is that the syndrome does lend itself to control with farm management changes.
These being spraying of any trees with ETC or caterpillers in general and feeding hay out in the field. The later being thought to keep the horses from grazing near trees that are infested.
The only diagnostic check so far is to do a fetal sonogram and look for an increased echogenicity in the amniotic and allantoic fluid, however, by this point it is to late. My suggestion is that you start "perimeter treatment" by throughly examining your farm and looking for catepillers and start spraying

No comments: