Fourth Michigan Horse Tests Positive for EHV-1

Two horses in Livingston County and two in Saginaw County have been identified with equine herpes virus type-1 since March 19.

The American Quarter Horse Journal

Editor's Note: The following is a statement from the Michigan Department of Agriculture and Rural Development on April 7, 2015:

A fourth horse was recently found to be positive for equine herpes virus type-1. This horse is the second horse to be found positive on a quarantined farm in Saginaw County, Michigan. The horse is under veterinary care. This means that there are two positive horses (one was already euthanized) at the Livingston County quarantined index farm and two positive horses at a quarantined Saginaw County farm.

The Michigan Department of Agriculture and Rural Development continues to follow up on all horses potentially exposed to the first Michigan EHV-1 positive horse reported on March 19. At this time, we consider all horses that attended a March 7 event in Barry County to be at the highest risk of exposure. We know from the progression of this outbreak that a secondary transmission is occurring. In other words, horses that attended the March 7 event may have been infected, shown only minimal signs of disease (fever, possibly a runny nose) and spread the disease to another horse.

If you have a horse that attended the March 7 event in Barry County and brought your horse home where there are other horses, those other horses are still at risk for getting and spreading disease. As MDARD finds these situations, additional quarantines may be placed for enforced isolation and monitoring of horse health.

There has been a lot of rumor regarding a travel ban for Michigan horses – this is untrue. Healthy horses who have had no exposure are under no travel restrictions. The best thing you can do for your horse is make informed choices. For example, if you had a horse at the March 7 event in Barry County, keep that horse, and all other horses, at your farm or stable until the likelihood of disease spread is minimized. The possibility of disease spread is minimized when all horses at the farm or stable have had no fever or other signs of disease for 28 days.

For horses who may be traveling out of state, you should work with your local veterinarian to obtain an interstate health certificate and your vet will determine if your horse should travel.


The following is a statement from the Michigan State University College of Veterinary Medicine on March 24:


An 8-year-old American Quarter Horse gelding, used for barrel racing, presented to Michigan State University Veterinary Medical Center March 18 for acute onset of neurologic disease. 


The gelding tested positive for equine herpes virus type-1 (EHV-1) and was placed in isolation. The gelding was euthanized March 21 due to deterioration of clinical signs in the face of aggressive supportive care. 


No other EHV-1 cases have been reported in Michigan at this time. All equine in-patients at MSU were tested March 21 for EHV-1. At that time all horses tested negative.


Use these 10 tips to protect your show horse before, during and after events from the threat of equine herpes virus type-1.