ehv-1 | Horse Racing Free Tips

EHV-1 Outbreak In Europe Improving; Now Found Stateside

Europe has recently experienced one of the worst outbreaks of equine herpes virus (EHV-1) in decades. The neurologic form of the disease has forced the cancellation of international competitions in 10 European countries, including France, Spain, Portugal, Belgium, Italy, Austria, Poland, the Netherlands, Germany and Slovakia. The cancellations remain in place until March 28.

The initial case of EHV-1 was confirmed at the CES Valencia Spring Tour showjumping competition; 83 of the 752 horses at the venue showed clinical signs and are currently being treated for the disease. Six horses have died. An additional 15 horses are being treated at off-site equine clinics.

All horses that had been in Valencia since Feb. 1 are blocked in the Fédération Equestre Internationale (FEI) database. They cannot compete in any FEI-sanctioned event until they complete EHV-1 testing requirements. The FEI is the governing body for international equine competitions. The USDA's Veterinary Services Department has no current international movement restrictions in place.

In the United States, one 8-year-old mare in Ocala, Fla., was confirmed infected with EHV-1 on March 1 and placed in isolation. Florida Animal Health officials have implemented biosecurity protocols and are monitoring the situation. Horse owners and caretakers are reminded to take precautions before introducing new horses to an existing herd.

Don’t Hesitate To Vaccinate For EHV With Other Core Vaccines

With the onset of the most serious EHV-1 outbreak Europe has seen in years, horse owners and caretakers are reminded of the necessity of vaccinating horses against the deadly disease. Questions have arisen regarding the best timing of vaccine administration — should the EHV vaccine be given concurrently with other AAEP-recommended core vaccines or should the vaccines be split into multiple doses?

Research suggests that vaccinations for equine influenza virus (EIV) and equine herpesvirus types 1 and 4 (EHV-1 and EHV-4) can safely be administered on the same day without compromising the horse's immune response.

Scientists from the Irish Equine Centre in Kildare divided 30 healthy horses into two groups to test the efficacy of the vaccines alone and used in tandem. The first group received the EIV vaccine and then a combination EHV-1 and EHV-4 vaccine two weeks apart. The second group was given both vaccines on the same day. Blood samples were taken from all horses before and after the vaccinations to measure antibody levels to EIV, EHV-1 and EHV-4.

Results showed that the horses vaccinated for both EHV and EIV on the same day had slightly higher antibody response to EIV vaccines than those horses that were vaccinated two weeks apart. There was no significant difference in EHV-1 and EHV-4 antibody response between the two groups.

The study team concludes that administering EIV and EHV-1 and -4 concurrently will not compromise the horse's immune system response.

Monkey See, Monkey Do: Will A Foal Mimic A Mare’s Neurologic Behavior?

Foals often mimic the behavior of their dams, copycatting everything from grazing to running to rolling and more. But what happens when a foal is born to a mare that has neurologic issues? Will it mimic the odd behaviors?

The staff at Mid-Atlantic Equine Medical Center has cared for many foals born to neurologically compromised mares, said Dr. Rodney Belgrave. Often the mares are afflicted with equine protozoal myeloencephalitis (EPM). Belgrave says he has not seen foals mimic the neurological signs their mothers exhibit.

However, foals can be born infected with organisms that cause neurologic disease. One of the organisms that causes EPM can be transmitted to the fetus from the placenta. However, infected foals may not demonstrate neurological signs until they are three months old.

Foals can also be born with equine herpesvirus type-1 (EHV-1) that is contracted from the dam, but many don't show neurologic signs of this disease, either.

The most common cause of neurologic disease in foals is neonatal encephalopathy, which occurs when the fetus is deprived of oxygen. This can be caused by a bacterial infection called placentitis or by a difficult birthing process. Affected foals often don't develop neurologic signs until 18 to 24 hours after birth.

In both cases, the lack of oxygen leads to fluid build up in brain tissue. Though alarming, the prognosis for neonatal encephalopathy is very good if the foals are treated early and appropriately.

Report: 18 Horses Ill As EHV-1 Sweeps Through Canadian Riding Stable

Staff at Venturing Hills Equestrian, a riding stable in Luskville, Quebec, Canada, have been working around the clock to try to save the farm's horses, which have been affected by the neurologic form of the equine herpes virus (EHV).

There are multiple strains of the equine herpes virus, including EHV-1, which can cause respiratory disease, abortion, neonatal death or neurological disease. Some horses exposed to the virus will develop neurologic signs. There is no cure for the neurological symptoms associated with EHV-1.

On Feb. 3, a healthy 5-year-old horse that lived at the farm began stumbling when he walked. His symptoms worsened and he was euthanized later that day. Samples the attending veterinarian had taken were positive for EHV-1. The second horse that died from EHV-1 was a 20-year-old horse on Valentine's Day. Both horses had been vaccinated for EHV.

Currently, 18 horses are sick, two are dead and five remain healthy. To try to keep the remaining horses disease free, staff has completely quarantined the healthy horses from the ill horses by building stalls on the property. They have also instituted biosecurity measures like limiting the people who see the infected horses, wearing hazmat suits and steaming hay nets to kill the virus.

Owner Rae Becke believes a new horse that arrived at the facility on January 15 brought the virus with him from Toronto. She later learned that three horses at the horse's former facility had died from the virus on Jan. 29. Becke was never informed of the situation, so the new horse was turned out with Venturing Hills' equine residents.