Equine Viral Arteritis: Update for the NIAA Equine Health Committee

 

Amy W. Mann, American Horse Council

 

 

I’ve been asked to provide a brief update on where we are with regard to addressing the problems associated with EAV shedder stallions and infective semen imported into the U.S.  I’d like to begin with a quick review of the reasons for our concerns of these animals and products and the need for action. 

 

You’ll recall that EAV carrier stallions and infective semen are freely imported into this country as it is the only major horse breeding nation not to regulate this disease.   In the past there have been abortions and deaths of neo-natal foals associated with outbreaks caused by the unknown status of imported stallions or infective semen. 

 

It was determined that action was needed because a significant number of top breeding stallions worldwide are EAV carriers and these stallions represent the best genetics in the horse industry.  Unfortunately, the U.S. has been and continues to be denied exports of many valuable stallions and their semen because of their infective state.

 

In the mid-1990’s, the AHC established a working group to review the issue and develop guidelines to assist stallion and mare owners who wish to use EAV shedder stallions when breeding to a susceptible mare.  Once the guidelines were developed we distributed them to our breed registries and then began to work with the regional divisions of the USAHA to get the endorsement of the state veterinarians.  A job harder than it looked.  We also, through the USAHA, sought assistance of USDA in regulating the importation of EAV shedder stallions and infective semen by determining the serological status of imported stallions with regard to EAV or the virus infectivity status of imported equine semen.

 

Our progress since then includes a wide distribution of the guidelines by the AHC including posting the guidelines on our website.  Some breed registries, particularly within the warmblood breeds, have instituted strict rules regarding the determination of EAV status of stallions that wish to be included in their studbooks.  Shedder stallions are not denied inclusion and mare owners are provided a copy of the guidelines if they wish to breed susceptible mares to a shedder stallion.

 

USDA has, with the tenacity of Dr. Cordes and the expertise of Dr. Timoney, produced an excellent video on EVA that has been widely distributed.  Dr. Cordes also coordinated a terrific video conference in which Dr. Cordes, Dr. Timoney, Dr. Giddens and myself briefed state veterinarians in four regions on the purpose of our efforts, the science behind it, the need for controlling EVA and the industry’s perspective on the situation.  Reaction was extremely positive, as it allowed state veterinarians to focus on the issue, learn about the disease and ask questions and provide input on the matter.  It was well attended and effective.

 

Another step was the publication of the Advanced Notice of Proposed rulemaking, known as the ANPR, in which we had numerous industry comments which overwhelmingly supported Option # 3 of the ANPR which, simplistically relayed, called for the determination of the serological status of an imported stallion with regard to EVA and then letting the state of destination handle the animal as it determined best.

 

This brings us to our current status.  Bluntly put, we are back to square one.  Despite all our efforts, EAV carrier stallions and infective semen are still freely imported into the U.S. and few states have taken action to address the disease within their borders.  While EVA remains a concern, interest in the disease seems to have waned.  There are fewer outbreaks reported in recent years and vaccine orders are down, according to Dr. Timoney.

 

The USDA does not feel it can implement an import program because we don’t have a domestic program.  And while three states do have regulations governing EVA and the existence and use of the voluntary breeding protocol for EVA, USDA does not feel these would be enough to justify an import protocol for EVA. 

 

To its credit, USDA did develop a plan to regulate EVA at a domestic level and at the point of import.  At a meeting in December between USDA and the AHC, including Dr. Timoney and Dr. Giddens this plan was discussed.  However, if the plan as proposed were implemented at this time the industry would not support it and it would, at best, be viewed as overly burdensome.  It was decided then that a renewed educational effort should be targeted to industry, state veterinarians and animal health officials on how to prevent and control the disease. 

 

EVA does remain a concern, especially since many of our horses are still being denied export because of their shedder status.  USDA should take this matter up with the European Commission as any European states have EVA programs (although often not enforced) for their own shedder stallions. Yet U.S. carrier stallions can not be imported into those same countries to conform with their EVA protocols. 

 

USDA agreed to address this issue with Europe, and the AHC continues to urge the USDA to approach the subject with Europe.  A mechanism for doing this is now available since a technical issues working group has now been formed between the US and the EU to address exactly these kinds of issues.

 

Also, agreed upon was the development of USDA endorsed guidelines, or a UM&R (uniform methods and rules) for EVA.  This will assist the states and the industry in setting up prevention and control programs and will send a message to the rest of the world that we intend to take this matter seriously, including the possibility of regulating EVA.  A meeting to begin this process is being planned for June.