Hold your horses - what horse owners need to know about EHM and EHV-1

Dr. Bruce Hutton
WSDA Field Veterinarian

Spring is just around the corner and horses are going to be coming together under stressful conditions whether for a weekend trail ride, jackpot roping, or a large, nationally-organized event – prime conditions for equine herpes virus (EHV). 

Just this month, a horse in King County tested positive for non-neuropathogenic EHV-1 neurologic strain. Unfortunately, the horse had to be euthanized.

There are multiple strains of EHV-1 in horses. A diagnosis of EHM is made when a horse is infected with EHV-1 and showing neurological signs independent of what strain of the virus the horse is infected with. 

To be clear, the horse in Washington was not infected with the strain of virus currently causing an EHM outbreak in California. 

The outbreak in California is caused by the neuropathogenic strain of EHV-1 which is more highly contagious and more deadly than the non-neuropathogenic strain. 

The horse diagnosed in Washington was infected with the non-neuropathogenic strain which usually causes only mild respiratory diseases. Unfortunately, this horse also developed neurological signs (EHM) and had to be euthanized. 

With this recent case and the recent cases in California, it’s a good time to review your knowledge of EHV-1 and equine herpes meyloencephalopathy (EHM), and make sure you have a robust biosecurity program to prevent the spread of disease associated with commingling of horses.

What to watch for 

Most horses have been exposed to, or infected with, the equine herpes virus by the time they are two years old.

There are several equine herpes viruses, with EHV-1 and 4 posing the greatest risk to the horse community. Symptoms of EHV-1 infection in horses include: 

• respiratory disease (rhinopneumonitis)
• abortions
• neonatal death
• neurological disease

EHV-4 produces a mild to moderate respiratory disease in foals, occasionally causes abortions, and in extremely rare cases develops into EHM. 

After an initial EHV-1 infection, the virus remains in the body in its latent form, essentially hiding from the immune system, waiting for the opportunity to revert to its active form. Stress, caused by traveling, training, overcrowding, or competition, is often the trigger for the virus to revert.  

Once active, EHV-1 is highly infectious and spreads quickly through direct contact with nasal secretions or aerosol droplets. Direct horse-to-horse contact does not require the horses to have actual physical contact, only direct contact with the nasal discharges of an infected horse. 

People can’t be infected by the virus, but they often facilitate its spread through contamination of hands, clothing, equipment, tack, trailers, stalls, feed buckets, water buckets, and many other items. In addition, aerosol droplets can travel several feet to infect other nearby horses.

Once infected with EHV-1, horses will usually exhibit signs of illness within four to six days.  Clinical signs range from mild respiratory to severe neurological deficits. Typical signs of respiratory disease include fever, discharge from the eyes and nose, slight cough, depression, going off feed, and swollen lymph nodes. Clinical signs of EHM include fever, depression, hind end weakness and incoordination, loss of tail tone, head tilt, urine dribbling, and may present as down and unable to rise. 

EHM cases often have minimal to no respiratory signs. Unlike respiratory disease, from which most horses recover, EHM is a life-threatening disease with no cure. Treatment is limited to supportive care and the prognosis is poor with a fatality rate as high as 30 percent.  

Even though EHV-1 is highly contagious and can quickly spread among horses, it doesn’t typically persist long in the environment and can be neutralized efficiently with good hygiene practices. In fact, EHV-1 is estimated to persist in the environment for less than 7 days and no more than 30 days under ideal conditions.  

Available vaccines can prevent the respiratory and abortion forms of EHV-I, but none are labeled as preventing EHM. Maintaining a vaccination protocol for the respiratory and abortion forms of EHV-1 decreases viral shedding and may decrease the incidence of EHM. 

Strong biosecurity measures, which should be in place even in the absence of an outbreak, are essential for limiting the spread of EHV-1 and EHM.

Protecting your horse

Here are some recommendations to minimize the spread of EHV-1 before, during, and after commingling at a show or event: 

1. Have a strong biosecurity plan and practice it at all times to prevent the spread of infectious agents.
2. Keep horses current on all recommended vaccines and have health papers in order.
3. Prevent horse-to-horse contact and provide each horse with its own equipment including tack, grooming equipment, water bucket, feed bucket and all other items. Do not share the equipment with other horses.
   
4. Keep people from touching your horse, especially around the face, nose, and neck. If people do touch your horse (groomers, hair braiders, veterinarians, etc.), insist they first wash their hands with soap and water, or use an alcohol-based hand sanitizer, and again after touching your horse. 
5. Bring several gallon jugs of your own water to water your horse so you won’t need to use a common hose.
6. If a common hose is used for watering, make sure the nozzle and any other part which could touch the water bucket is disinfected. After the hose is disinfected, hold it high above the water bucket, do not touch any part of the bucket with the hose. Do not immerse the hose end into your water bucket when filling it. 
7. Disinfect your shoes or boots right after the show and before returning to your barn.
8. Wash your clothes immediately after attending a show.
9. Don’t stable your horse with other horses. If you can, keep your horse in its trailer. If you must stable it, clean, and disinfect the area thoroughly.
10. Check your horse’s temperature twice daily for at least two weeks after returning home and monitor them for the respiratory or neurological signs mentioned above. If a fever develops or signs appear, contact your veterinarian immediately and let them know you have recently traveled with your horse, and the particulars of the show

Reportable diseases

EHV-1 and EHM are reportable diseases in the state of Washington. Visit our Reportable Diseases webpage to report cases. 

After contacting your veterinarian, it is likely they will take nasal swabs and blood samples to check for EHV-1. It is important to isolate your horse and treat them as if they were infected until laboratory results come in.

Prevention, through good planning and good biosecurity plans, is always better than dealing with an outbreak. The Equine Disease Communication Center (EDCC) at equinediseasecc.org/alerts provides a good online tool for horse owners interested in checking out the current equine disease alerts in the United States and Canada. It’s always a good idea to check before you go.

WSDA awards Director Citation to retiring director of state hop commission

Amber Betts
WSDA Communications

Ann George (L), accepts the WSDA Director's 

Citation award, presented by WSDA's Brad White (R). 

The Washington State Department of Agriculture (WSDA) director’s citation award is an honor that is given to recognize those in the ag community who have devoted their lives to promote and enhance agriculture in our state.

So it was no surprise to those around her that Ann George, Executive Director of the Washington State Hop Commission, was presented with the honor at a regular Washington Hop Commission meeting March 23, 2022.

“Ann has shown incredible dedication, devotion, and passion for the promotion of hops and agriculture in general in our state. As she prepares to retire, she leaves quite the legacy behind,” WSDA Director Derek Sandison said. “It is my absolute honor to present her with this award.”

Dr. Brad White, WSDA’s plant protection assistant director, presented the award on behalf of WSDA Director Sandison at a recent meeting of the Washington Hop Commission.

Ann served as the Executive Director of the Washington Hop Commission and Hop Growers of Washington since 1987. Her resume and list of accomplishments do not stop there.

She also served as the executive director of Hop Growers of America since 2007. As she prepares for retirement, Ann leaves a 35-year legacy, playing a key role in forming the US Hop Industry Plant Protection Committee, an international regulatory harmonization program. She also was crucial in forming the HGA Best Practices Committee and Good Bines educational platform. If that wasn’t enough to make her mark on agriculture in the state and across the nation, she also manages Science and Technical programs, political and regulatory efforts, and has secured numerous grants to expand the hop industry’s resources.

Today, Washington produces more hops than any other state in the nation, and hops are among our top 10 crops, with revenues of $445 million in 2019.

“It’s important to note, this isn’t an annual award,” Megan Finkenbinder, WSDA fairs and commissions administrator, said. “It’s only given to those who have truly risen to the level of contribution to the industry and deserve this prestigious award,”.

Visit our Director's Citation webpage to learn about previous recipients and how to nominate someone for recognition as exceptional supporters of our state's farming, ranching, and food producing community.

Drought and soil survey for Washington’s dryland wheat farmers

Dani Gelardi
WSDA Soil Health Scientist

Are you a dryland wheat farmer affected by the 2021 drought? If you are, the Washington State Department of Agriculture needs your help. 

As part of its continuing work addressing soil health, WSDA is looking for information from dryland wheat farmers about soil management practices, particularly relating to drought. This information will be critical for the researchers involved in the Washington Soil Health Initiative as they learn ways to support agricultural operations enduring drought conditions in the future.

The Drought and Soil Survey will be open until May 1. The survey is detailed, but can be completed over multiple sessions and does not have to be filled out all at once. 

Questions will cover how you manage your soils, the cost of implementing different soil management practices, and the effects of the 2021 drought on your operations.

Results will increase our understanding of dryland production and help us communicate with decision makers so we can better support you. Survey takers will be anonymous, but we will make a summary of the responses available to the agricultural community. 

This survey is being conducted on behalf of the Washington Soil Health Initiative, a joint effort of WSDA, Washington State University, and the Washington State Conservation Commission to study soil health in our state and explore ways to improve it.

Soil health focuses on how well a soil system supports plants, animals, and people. It also recognizes the living nature of soils and the importance of soil microorganisms. Visit agr.wa.gov/AgScience to find our soil health page.

WSDA announces awardees of Local Meat Processing Capacity Grants

Amber Betts
WSDA Communications 

Grants support small meat processing
operations in Washington.

The COVID-19 pandemic made it clear that there is a need for more meat processing services for small farms and ranches in Washington, to strengthen food supply chains and local food economies. This week Washington State Department of Agriculture (WSDA) identified grant recipients to support small meat processing operations serving direct-marketing farms and ranches around the state.

WSDA received an overwhelming response to the grant opportunity with 112 applications for the WSDA Local Meat Processing Capacity Grants.  Applications totaled more than $27 million in funding requests. The Washington State Legislature allocated $3.6 million for this grant. 

“We received many great project applications and truly wished for the ability to fund more of the clearly-demonstrated need within the small meat processing industry,” Alyssa Jumars, Local Meat Marketing and Capacity Specialist for the Regional Markets Program said. “We are grateful to all applicants for their time and for their commitment to serving small farms and ranches.”

The purpose of the grant program is to increase access to livestock and poultry processing for small to midsize farmers and ranchers so they can better serve people in Washington state. 

The grants will help the selected small and midsize meat processors expand their capacity to serve Washington farmers and ranchers that sell their meat and poultry products directly to consumers, stores, food hubs, restaurants, schools, and other local buyers.  

A dozen expert reviewers from across the state reviewed anonymized applications. Reviewers scored applications based on consideration of a project’s ability to expand harvest or processing capacity, and provide direct benefit to small, direct-marketing farms. A project’s achievability was also a key consideration (ie: reasonableness of project and project costs, level of planning, readiness to implement, and achievability on the timeline).  

Grants were available in two categories: “Small Projects” and “Large Projects.” Given the amount of applications, reviewers agreed to fund a larger number of small projects, even at much smaller amounts – in order to spread resources as widely as possible across the state. Geographic areas with particularly limited access to meat processing services received additional consideration and funds for top-scoring projects. WSDA awarded 36 projects in the “small projects” category among 22 different counties in Washington. 

In the large projects category, reviewers funded the highest-scoring projects at an amount that will allow them to significantly expand capacity and make a notable impact. WSDA awarded four projects in this category in as many counties. 

For more information about the awards, visit our grants page. These grants contribute to a larger WSDA initiative to Focus on Food. This initiative supports Washington’s food system and works to ensure that safe, nutritious food is effectively produced, distributed, and delivered to people who want and need it. 

Biosecurity and protecting your horse from strangles

Dr. Amber Itle
Washington State Veterinarian 

This week, a Snohomish County horse that recently attended a show in Whatcom County was diagnosed with strangles, Streptococcus equi, an endemic bacterial infection that is rarely fatal, but as the name suggests, can affect a horse’s respiratory system. 

There is no evidence the horse was contagious at the time or that it contracted the disease at the show.  

Since January, there have been reports of six other confirmed, laboratory-diagnosed cases of strangles in Okanagan, Clallam, Kitsap, and Pierce counties.

Private veterinarians usually manage the strangles cases reported to the Washington State Veterinarian’s Office, including imposing self-quarantine, implementing biosecurity measures, and executing testing protocols. WSDA field veterinarians contact those veterinarians to monitor these cases and provide support, including issuing official quarantine orders in some cases. 

When a quarantine is in effect, no horses are allowed to move on or off the premises, attend horse shows, or travel. It is actually against the law to expose other animals to contagious, infectious, or communicable diseases.

How to protect your horse against strangles

Any time you attend a show, WSDA recommends monitoring horse’s body temperatures twice a day and isolating horses for up to three weeks to monitor for disease. Oftentimes, fever will precede illness and early detection can help prevent disease transmission. The incubation period (time of exposure to time of clinical signs) can range from 3-14 days. While strangles is a concern to many horse owners, there have also been several cases of Equine Herpes Myeloencephalopathy reported in California, a potentially fatal viral disease showcasing why biosecurity practices are critical for horses that attend exhibitions or other events.  

Strangles is rarely fatal and the prognosis for recovery is usually very good with proper care. Symptoms include:

• Fever
• Abscesses in the mandibular lymph nodes
• Nasal discharge that can include thick white and yellow mucus
• Inflammation of the throat
• Difficulty swallowing
• Wheezing
• Coughing
• In rare cases, bleeding from the capillaries

Good biosecurity practices are the best defense against the disease. The Equine Disease Communication Center’s “What is biosecurity?” offers excellent recommendations. 

The EDCC also recommends the following:

• When possible, isolate new horses for up to three weeks when they are being introduced to a new facility. 
• If you have handled an infected animal during an outbreak, avoid coming in contact with susceptible animals. 
• Wear protective clothing, avoid using the same equipment on multiple animals, and disinfect both your hands and equipment when moving between animals.

This “Strangles Fact Sheet” from the EDCC has more information on this disease, tips and suggestions.

Remember to notify WSDA if you become aware of a reportable disease by visiting our “Reportable Diseases” webpage.