Mare Reproductive Loss Syndrome (MRLS)


Eastern Tent Caterpillar Eggs Could Hatch Early in Kentucky

February 23, 2017

Entomologists predict that this year's egg hatch could beat the previous record for early hatching "soundly."... Read More


Eastern Tent Caterpillar Egg Hatch Underway in Kentucky

March 18, 2016

Eastern tent caterpillar consumption can cause late-term foal losses, early- and late-term fetal losses, and weak foals.... Read More


What's Lurking in Your Forage?

November 09, 2015

From toxins and molds to opossum droppings and animal carcasses, forage can contain a variety of harmful contaminants.... Read More


Caterpillars that Cause Abortion in Mares

April 04, 2015

Learn how researchers determined that hairy, bristly caterpillars can cause abortions and how to protect mares.... Read More


Eastern Tent Caterpillar Egg Hatch Begins in Kentucky

March 26, 2015

Caterpillar consumption by pregnant mares can lead to fetal loss, late-term foal loss, or weak foals.... Read More


Emerging Equine Diseases: What You Should Know

March 23, 2015

Learn about emergent diseases and what steps we can take to help stop illnesses' spread into unaffected countries.... Read More


Eastern Tent Caterpillars on the Move in Central Kentucky

May 10, 2014

Experts advise farm managers to ensure pregnant mares do not come in contact with crawling caterpillars.... Read More


Winter No Threat to Eastern Tent Caterpillar Eggs

March 14, 2014

The Eastern tent caterpillar has been implicated as the cause of mare reproductive loss syndrome (MRLS).... Read More

Viable Eastern tent caterpillar egg masses will be partly or completely covered with a brownish coating, without obvious holes. They are found on twigs of cherry and other trees on twigs.


Eastern Tent Caterpillar Outlook for Spring 2013

February 13, 2013

Experts report that the eastern tent caterpillar egg hatch will likely begin in mid-March in Central Kentucky.... Read More

Straw, the byproduct of grain production, is economical horse bedding. While it’s not as absorbent as other options, straw is often recommended for foaling stalls because it won’t stick to wet newborns.


Fertilization and Early Pregnancy Loss in Mares

April 27, 2012

One of the most important causes of embryo loss during early gestation is post-breeding endometritis.... Read More


Eastern Tent Caterpillar Egg Hatch Under Way in Central Ky.

March 24, 2012

Experts report that this year's Eastern tent caterpillar egg hatch is about a week ahead of average.... Read More


Eastern Tent Caterpillars Hatching Earlier This Year

March 01, 2012

Research has proven the caterpillars caused outbreaks of mare reproductive loss syndrome (MRLS).... Read More


Proper Use of Antibiotics for Uterine Infections (AAEP 2011)

February 01, 2012

Ensure a bacterial infection that will respond to antibiotics is actually present before beginning treatment.... Read More


Time to Assess Eastern Tent Caterpillar Populations

April 21, 2011

Eastern tent caterpillars (ETC) were identified as the cause of foal loss during the mare reproductive loss syndrome outbreaks in 1999-2001. Over the last three years, ETC populations in Central Kentucky have been increasing gradually but there are ... Read More


Eastern Tent Caterpillar Egg Hatch Under Way

March 21, 2011

Experts report that Eastern tent caterpillar eggs have begun hatching in Central Kentucky, just as leaf buds are swelling on wild cherry trees. While it is too early to tell what 2011 caterpillar numbers will be, populations have been increasing ... Read More


Second Annual Breeders' Short Course Recap

January 27, 2011

The University of Kentucky College of Agriculture partnered with the University of Minnesota (U of M) to present the 2nd Annual Kentucky Breeders' Short Course held Jan. 21 and 22 in Lexington. The first day of the course was designed for ... Read More


Equine Abortion of Unknown Cause

January 22, 2011

Pregnancy loss is relatively common in horses. Only 80% of mares bred give birth to a live foal at term. The loss of the developing foal (fetus) during gestation can fall under one of two categories: early embryonic loss, in which the loss of a fetus... Read More


MRLS Research Stresses Possible Convergence of Climate, Management Factors

July 21, 2010

The cases of mare reproductive loss syndrome (MRLS) that Lexington, Ky., experienced in 2001 were a symptom of many issues converging, according to laboratory medicine specialist Jennifer Taylor of Melbourne, Australia. Taylor presented her findings ... Read More


CEM: Lower-Cost Stallion Testing Continues

May 20, 2010

In an effort to show that Contagious Equine Metritis (CEM) does not exist or is at very low levels in the US equine horse population, the USDA is offering lower-cost testing to owners of active breeding stallions through August. It is part of a... Read More


New Knowledge Comes Through New Research

April 25, 2010

Eastern tent caterpillars are numerous on our small central Kentucky farm this year. They have defoliated the spring leaf growth on most of the wild black cherry trees and are now crawling around in great numbers on board fences, stone walls, a... Read More


Eastern Tent Caterpillar Egg Hatch Under Way, Numbers Up Again

April 23, 2010

Experts report Eastern tent caterpillars are hatching in central Kentucky in increasing numbers.

"Some tents are the size of baseballs now, so they will be easy to see," said Lee Townsend, PhD, and University of Kentucky Co... Read More


Eastern Tent Caterpillar Numbers Up Again

April 19, 2010

Experts in Kentucky report that eastern tent caterpillar numbers are up for the third consecutive year, although populations vary from location to location.

According to Lee Townsend, University of Kentucky College of Agriculture entomologist, ... Read More


MRLS Foal Losses in Kentucky Increased Slightly in 2009

August 12, 2009

Between May 5 and June 15, the Livestock Disease Diagnostic Center (LDDC) diagnosed 13 foal loss cases caused by mare reproductive loss syndrome (MRLS) in Central Kentucky. This number was up slightly from 2003-2008 when only three to five cases... Read More


Kentucky Reports Mare Reproductive Loss Syndrome Cases

May 13, 2009

The University of Kentucky Livestock Disease Diagnostic Center (LDDC) reported today (May 13) that two fetal necropsy cases had findings consistent with mare reproductive loss syndrome (MRLS), the disease that in 2001-2002 in Kentucky caused an... Read More


MRLS: Eastern Tent Caterpillar Numbers Up

March 25, 2009

Eastern tent caterpillars have begun hatching in Central Kentucky--and their population numbers are trending up.

"Populations of the Eastern tent caterpillar have increased noticeably over the past three years," said Lee Townsend, PhD,... Read More