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.

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.

A call for vigilance: keep deadly poultry disease out of our backyard

Dr. Brian Joseph
Washington State Veterinarian

An outbreak of a deadly poultry disease in southern California is cause for local poultry growers and those with backyard flocks to keep their guard up.

If you have poultry, we ask that you be on the lookout for signs of Virulent Newcastle Disease (vND) and report any cases to the WSDA Sick Bird Hotline at 1-800-606-3056. 

The warning comes on the heels of an outbreak that began this May in Southern California, where the virus appeared and spread through backyard poultry flocks in Los Angeles, Riverside and San Bernardino counties. The disease has not been detected in any domestic poultry in Washington – we would like to keep it that way.

Watch for unusually large numbers of poultry deaths or symptoms such as swelling around the eyes and neck, dripping of fluid from the beak and nasal area, coughing, sneezing, twisting of the head and neck, greenish diarrhea, decreased appetite, or decreased egg production.

Commonly known as exotic Newcastle disease, vND spreads quickly with high rates of illness and mortality for domestic poultry. 

The vND virus can infect many bird species including chickens, turkeys, ducks, geese, and game birds. Infected birds shed large amounts of virus in respiratory fluids and feces.

Backyard chickens are at greater risk and are highly susceptible because they can be “silently” infected by other birds, such as parrots, that show few or no signs of illness.

No commercial poultry operations have been affected so far and properly cooked poultry poses no risk to humans when consumed. For poultry, the virus can be transferred between facilities on clothing, feed, equipment or by moving birds, which may appear unaffected. 

Prevention through biosecurity 

The key to preventing vND infection is to practice consistent biosecurity. Recommendations from CDFA include:

• Use dedicated clothing and footwear or wear disposable coveralls and booties when visiting birds
• If exposed to poultry waste, change clothes and footwear, disinfect any items used and wash your car
• Use footbaths for the bottoms of shoes or plastic botties at entry/exit of poultry enclosures
• Practice good hygiene for your hands and disinfect equipment
• Prevent wild birds from entering poultry enclosures
• Carcasses of dead birds should be double bagged in plastic garbage bags
• DO NOT dump bird carcasses on the roadside or other exposed locations
• Avoid gatherings where poultry are present
• Avoid sharing or borrowing equipment from other poultry owners
• Avoid moving your birds or purchasing new additions unless they are from an NPIP certified seller.

Visit our avian health webpage if you have questions about exotic Newcastle disease, or how to keep your birds safe and healthy. 

Washington rabbit owners - be aware of deadly rabbit virus reported in British Columbia

Dr. Lyndon Badcoe 
Animal Health Program, 
Field veterinarian 

A deadly virus that infects both domestic and feral European rabbits has been detected in British Columbia, and is good reason for owners of rabbits or fair managers with rabbit shows to take extra precautions this year. It is not known how this new rabbit hemorrhagic disease (RHD) serotype virus 2 would affect native North American wild rabbits.

The Canadian Food Inspection Agency (CFIA) reported the detection of rabbit hemorrhagic disease (RHD) serotype virus 2, or RHDV2, on March 8. Rabbit deaths were reported on Vancouver Island, and there are tests in progress to determine if this disease has spread to the Canadian mainland. Officials in Canada are currently reviewing a vaccine for RHDV2, but there is no vaccine available in the U.S.

Here is an in-depth, current report on rabbit hemorrhagic disease from Iowa State University's Center for Food Security and Public Health.

Rabbit hemorrhagic disease, or RHD, is easily spread among rabbits, causes a high rate of infection and death, and the agent (calicivirus) is very stable in the environment. The first signs of the disease can take up to nine days following infection, but affected rabbits can also develop a fever and die within 12 to 36 hours.

European rabbits have been shown to be affected by RHD and are the type of rabbit most commonly used as show animals by 4H, FFA and other hobby groups. The rabbits that died in British Columbia were European rabbits that had gone feral. It is not known how the virus would affect native North American rabbits, which are typically cottontail and jack rabbits.

Protecting your rabbit 

Since there are no vaccines currently available in the U.S. for the virus, the best way to protect your rabbits is by practicing good biosecurity, including good sanitation and disinfection, and keeping new rabbits separated from your existing flock.

With fairs, shows and exhibitions coming up soon, there is always the concern that someone could bring an infected rabbit from an area where the disease has been reported.

Remember that a certificate of veterinary inspection must accompany all animals entering Washington State, including rabbits.

Rabbits can shed the virus in urine or feces for as long as four weeks after infection. It can be spread on contaminated food, bedding, fur and water, or by direct contact with infected animals or contaminated objects. Rabbits can become infected through oral, nasal, or conjunctival routes in the eyes.

While the disease does not affect humans, it can be spread through contaminated clothing or vehicles, or other animal handling equipment. Biting insects, birds, rodents, and wild animals can also spread the virus. The virus can survive for long periods of time in the environment and remain infectious to animals.

Signs of infection in rabbits include:

• Listlessness
• Lack of appetite
• Congested membranes around the eyes 
• Nervousness 
• Lack of coordination 
• Excitement or paddling 
• Difficulty breathing 
• Blood-stained, frothy nasal discharge upon death

If you notice any of the symptoms listed above, contact your veterinarian. Rabbit hemorrhagic disease must be reported to state or federal authorities immediately upon diagnosis or suspicion of the disease.

To report a diagnosis or an unexplained increase in deaths among rabbits, you can contact WSDA at 360-902-1878 or 1-800-606-3056. Wild rabbit die-offs can be reported at wildlife.health@dfw.wa.gov or by visiting www.wdfw.wa.gov/conservation/health to file a report online.

Rabbit hemorrhagic disease in the RHD form has occurred in the U.S. before, back in 2000 in Iowa and in 2001 in Michigan, New York and Utah. However, the outbreaks were restricted to small groups of affected rabbits. RHDV2 has never been reported in the U.S.

Tips for horse owners – protecting your horse from equine herpes virus

Dr. Brian Joseph
Washington State Veterinarian 

Last week, WSDA was notified of a laboratory-verified case of equine herpes virus myeloencephalopathy or EHV-1, neuropathogenic strain, in King County.  EHV-1, in its neurotropic form, is a highly contagious virus that can be fatal to horses but will not infect people.
  
WSDA immediately put a quarantine in place and has been testing horses that were housed near the first infected horse and horses showing clinical signs of infection. Work has also begun to trace animals that may have come into contact with the first infected horse. So far, five additional horses at the stable have been found to be infected and are being closely monitored.

Given the highly infectious nature of the virus, WSDA is urging horse owners to follow these recommendations:

• Watch your horse for signs of possible infection, such as:
• Fever of 102.5F or higher
• Discharge from the eyes or nose
• Respiratory symptoms
• Swelling of the limbs
• Spontaneous abortions
• Neurological signs such as unsteady gait, weakness, urine dripping, lack of tail tone and recumbency.
• Check your horse’s temperature twice daily, ideally first thing in the morning, and last thing at night. Also, check before administering medications as some can lower body temperature.
• Notify your veterinarian immediately if you detect any of the symptoms above. Your veterinarian may want to take nasal swabs for virus detection or blood samples for evidence of exposure to EHV-1.

Testing and vaccines

Suspected cases should be checked for EHV-1 by a veterinarian. The Washington Animal Disease Diagnostic Laboratory in Pullman provides EHV-1 testing, including differentiating the EHV-1 neuropathogenic strain. Veterinarians can contact WADDL at (509) 335-9696 to submit a red top (serum) blood tube, and a lavender top (whole blood) tube and nasal swabs.

Although there are several EHV-1 vaccines available that control respiratory disease or abortion in horses, none of the vaccines provide immunity against EHV-1, neurotropic form.

Keep it clean and protect your horse

The disease is spread from horse to horse through direct contact, on feed, tack and equipment. While people cannot be infected by the virus, they can carry it on their clothes or hands. Here are some biosecurity steps horse owners should follow to protect their animals from becoming infected or spreading this virus:

1. Wash hands, clothing and equipment and avoid using the same equipment on different horses.
2. Monitor all horses on your premises for symptoms.
3. Limit direct horse-to-horse contact.
4. Limit stress to horses.
5. Clean barn areas, stables, trailers or other equine contact surfaces thoroughly, removing all organic matter (dirt, nasal secretions, uneaten feed, manure, etc.), then apply a disinfectant. Organic material decreases the effectiveness of disinfectants. Be sure to follow the manufacturer’s recommendations when mixing disinfectants and for contact time.
6. Use footwear disinfectant and hand sanitizer when moving between areas.
7. If you have a potentially exposed horse, restrict human, pet and vehicle traffic from the area where the exposed horse is stabled.
8. Clean all shared equipment and shared areas, again removing dirt and manure before application of a disinfectant.
9. Self-quarantine any horses with possible symptoms away from other horses and contact your veterinarian immediately.

The time between exposure and illness from EHV-1 varies from two to 14 days. By self-quarantining animals with possible symptoms, practicing good biosecurity on your property and during travel, and contacting your veterinarian as soon as you suspect possible symptoms, horse owners can do a lot to prevent further spread of the virus.

WSDA monitoring flock after waterfowl test positive for low pathogenic avian flu

Dr. Brian Joseph
Washington State Veterinarian

Washington State Department of Agriculture (WSDA) veterinarians detected a low pathogenic strain of avian influenza (LPAI H5) in a flock of waterfowl last weekend during a routine test of open class exhibition poultry at the Central Washington Fair in Yakima County.

Recent reports of these positive test results should not be cause for alarm. Although it’s always important to monitor flocks which have tested positive for an avian influenza strain, this low pathogenic strain is not the same as the HPAI H5N1 strain that makes people sick in other parts of the world. It is the strain of LPAI known to commonly circulate in North American waterfowl which does not readily infect chickens, although it can.

WSDA animal health specialists said this strain of
avian influenza is low risk for poultry and no risk to humans.

While it can potentially spread to domestic poultry or mutate into high pathogenic avian flu, we closely monitor any flocks that test positive for LPAI H5 or H7 to make sure we can respond quickly if circumstances change.

On Friday evening, Sept. 29, our veterinarians were notified that the duck flock from Lewis County tested positive for low pathogenic avian influenza. The owners were advised to remove their birds from the fair and return them to the home farm. They cooperated and removed the flock the next morning. WSDA also issued “stop movement” orders to prevent the birds from being moved and to reduce chances that the disease would spread.

Moving forward
WSDA has partnered with the U.S.Department of Agriculture (USDA) to develop a continued health plan for the flock. There will be no depopulation in this case, and state officials will conduct further testing on the flock 21 days after the first test.

To improve biosecurity and help prevent infection, we urge you to keep any domestic ducks in your flock, and their water sources, separate from your chickens and wild ducks.

If you have any questions, email ahealth@agr.wa.gov to reach our avian health specialists.

Swine health recommendations for pig exhibitors

Dr. Minden Buswell and Dr. Dana Dobbs
WSDA Veterinarians

Showing pigs at fairs is a time-honored farming tradition, but it puts pigs in close contact with each other and people. They’re also in a new environment with unfamiliar animals and around potentially disease spreading equipment, like brushes and boots. These factors can increase the risk of disease for the pigs.

Some diseases can transmit between humans and pigs, not just from animal to animal. One example is Influenza A, or “Swine Flu,” which has been a problem at fairs in recent years.

Pigs shown at the 2015 Washington State Fair.

Another illness, Seneca Valley Virus (SVV) has recently been on the rise. Also called Senecavirus A, it’s an unfamiliar disease that presents symptoms similar to foot-and-mouth-disease (FMD). The only way to tell the difference is through veterinary diagnostic tests, so alert your veterinarian if you find blisters around the snout, mouth or hooves, or notice general symptoms of illness like fever, lethargy and loss of appetite.

Before the exhibition or show

To keep your pigs healthy and limit the spread of disease, make sure you are meeting exhibition health requirements. In addition, it is a good idea take some swine health precautions.

• Make a biosecurity plan well before you head to an exhibition.
• A biosecurity plan involves preparing for shows, understanding disease risk factors and signs of illness, managing pig health and cleanliness while at an exhibition, and caring for your pig afterward.
• Have your paperwork with you at the fair. 
• Files should include up-to-date health certificates, including your name, contact information, farm address and premise identification number (PIN). 
• The health certificate should also provide updated information about each pig, such as individual identification in the form of a unique number on the PIN tag, and a physical description.
• Keep your veterinarian’s phone number in your barn with your pig’s papers and in your cell phone. 
• Use an individual, readable identification method for each pig.
• Individual identification is a helpful way to identify a pig in the event of a health issue or validation of ownership. 

At the exhibition or show

At a fair, exhibition, or sale, be sure to assess your pigs’ health on a daily basis. Here are some other recommendations:

• Look for common signs of illness - fever (a rectal temperature higher than 102.5), loss of appetite, lethargy, coughing, nasal discharge, diarrhea, and difficulty breathing (also called “thumping”) are all signs something may be amiss.
• Keep the area clean by washing, disinfecting and drying equipment.
• Do not share equipment (such as buckets, brushes, restraint devices, etc.) with other exhibitors.
• Wash your hands or at least use hand sanitizer after handling animals and before going to other animal exhibits.
• Change barn clothes after handling animals, especially before going to other animal exhibits.
• Report any health issues to the exhibit manager and show veterinarian immediately.

After the exhibition/show

When pigs are brought home after the fair, disease risk can be high. Pigs from different farms are brought together and comingled with each other. Just like people can spread illness by comingling with others in a public space, pigs from varying locations and health statuses can spread illness to each other. It’s a good idea to isolate returning pigs.

• Upon returning home, establish an isolation plan with your veterinarian. An isolation period should last between seven and 30 days.
• The isolation area should be clearly designated and far away from other pigs which have not been to an exhibit.
• Perform chores for isolated pigs at the end of the day, after you’ve worked with other pigs.
• Keep clothes, tools and equipment separate for each location.
• You can also use disposable coveralls and boots.
• Clean and wash your trailer before using it to haul other animals.

Signage at the 2015 Washington State Fair.

Healthy, happy pigs are an important part of the showing experience, and create a valuable learning experience for those unfamiliar with agriculture and animal husbandry. Keep your pig’s area clean, watch for disease symptoms, and know who to contact if you suspect a health issue.

For more information, visit www.swinehealth.org/fact-sheets, or view www.pork.org/showpigs for additional biosecurity resources.

To learn more about Seneca Valley Virus, please refer to this fact sheet. 

WSDA fruit tree certification gets state-of-the-art greenhouse

Karla Salp
Communications

Director Sandison cuts greenhouse ribbon with project partners

WSDA Director Derek Sandison had the rare opportunity to dedicate a new greenhouse for the agency’s Fruit Tree Certification program on May 11.

For decades, WSDA has been renting space from Washington State University at their Prosser research station. There, WSDA conducted tests on new nursery stock to ensure that the plant materials entering our state’s nurseries were free of disease.

However, the increasing demand for disease-free plant materials for Washington’s booming fruit tree industry and the limitations of the existing greenhouse meant that it was time for WSDA to have a greenhouse of its own.

Building the greenhouse has taken several years and was the result of a remarkable partnership between WSDA, WSU, and the tree fruit industry. About 35 people attended the dedication ceremony – an indication both of the strong partnerships involved in building the greenhouse as well as the importance of the certification program to Washington’s fruit tree industry.

Dedication attendees get a greenhouse tour

Attendees at the dedication were treated to a tour, which included the three separate greenhouse bays. The newly dedicated 5,000 square foot state-of-the-art greenhouse is fully automated, featuring improved temperature and irrigation controls. Each growing bay is computer-controlled to maintain temperature ranges at which different fruit tree pathogens thrive.

The increased space and advances in the greenhouse technology enable WSDA fruit tree certification specialists to test trees at a greater rate than they have been able to in the past.

By screening for these fruit tree diseases, WSDA can ensure that Washington fruit tree nursery stock remains disease-free. This promotes not only the health of Washington orchards but ensures that Washington fruit trees can also be exported anywhere in the world.

Wish you could have been there? If you missed the dedication ceremony, you can still watch it on Facebook!

Tips for horse owners – protecting your animal from Equine Herpesvirus

Dr. Scott Haskell
Assistant State Veterinarian

Late last week, the Department of Agriculture was notified of one laboratory-verified case of Equine Herpesvirus Myeloencephalopathy, or EHV-1 wildtype, in Washington.

EHV-1 is a highly contagious virus that can be fatal to horses. The disease is spread from horse to horse through direct contact, on feed, tack and equipment. While people are not made sick by the virus, they can carry the virus on their clothes or hands. Horse owners should carefully wash their hands and equipment to prevent the spread of the virus.

WSDA is not currently establishing any quarantine, but our field veterinarians are actively tracing all areas where the infected horse might have contacted other animals.

Given the high risk of contamination, here are additional recommendations for horse owners.

Watch for symptoms
Closely observe your horse and look for signs of possible infection, which include:

• Fever of 102.5 degrees F or higher
• Discharge from eyes or nose
• Limb edema or swelling
• Spontaneous abortions
• Neurologic signs such as an unsteady gait, weakness, urine dribbling, lack of tail tone and recumbency.

Be sure to obtain and record the body temperatures of all horses on the premises twice a day, ideally first thing in the morning and last thing at night, and always before administering medications since some can decrease body temperature.

Let your veterinarian know if you detect a fever or notice any of the other symptoms listed. The veterinarian may want to take nasal swabs or blood samples to test for EHV-1.

EHV-1 testing at WSU
Suspected cases should be checked for both West Nile Virus and EHV1 by a veterinarian.  The Washington Animal Disease Diagnostic Laboratory in Pullman is providing testing.

Veterinarians should contact WADDL at 509-335-9696 to submit a red top and lavender top tube with nasal swabs directly to Dr. Jim Everman or Dr. Kevin Snekvik at WADDL.

Vaccines
It’s not too late to vaccinate your horse against EHV and there are a number of vaccines available.

Several EHV-1 vaccines available in North America carry a label claim for the control of respiratory disease induced by EHV-1 and EHV-4. These are multi-component inactivated vaccines specifically, Prestige® (Merck), Calvenza® (Boehringer Ingelheim Vetmedica) and Fluvac Innovator® (Zoetis) and the modified live vaccine Rhinomune® (Boehringer Ingelheim Vetmedica).

There are also two EHV-1 vaccines licensed for the control of abortion and respiratory disease. These vaccines are single-component inactivated vaccines, namely Pneumabort-K® (Zoetis) and Prodigy® (Merck).

Biosecurity – steps to protect your horse and others
To protect your horse from becoming infected, and help limit the potential spread of this virus, there are several things all horse owners should be doing.

1. Monitor all horses on your premises.
2. Limit direct horse-to-horse contact.
3. Limit stress to horses.
4. Don’t share equipment.
5. Clean barn areas, stables, trailers, or other equine contact surfaces thoroughly, removing all organic matter (dirt, nasal secretions, uneaten feed, manure, etc.) before applying a disinfectant. Organic material decreases the effectiveness of any disinfectant, especially if 10% bleach is used.
6. Use footwear disinfectant and hand sanitizer where indicated.
7. If you have a potentially exposed horse, restrict human, pet and vehicle traffic from the area where the exposed horse is stabled.
8. Clean all shared equipment and shared areas, again removing dirt and manure before application of a disinfectant.
9. Self-quarantine animals with questionable sysmptoms.
10. If you have mules, isolate them from horses since recent studies suggest mules can be silent carriers of the virus.

The time of exposure to illness of EHV-1 is typically two to 14 days. By self-quarantining animals with questionable symptoms, vaccinating horses for EHV-1 and West Nile virus, and practicing good biosecurity on the farm and during travel, horse owners can do a lot to help prevent further spread of the virus.

We’ll be sure to provide any updates here on the AgBriefs blog.

Avian influenza – spread the word, protect your birds

Dr. Joe Baker

Washington State Veterinarian 

Fall is coming and with it a renewed risk of highly pathogenic avian influenza, or HPAI. But first, some background on why this is such a serious cause for concern.

In the fall of 2014, Washington became the first state to have flocks infected with highly-pathogenic avian influenza, or HPAI. When the outbreak was over, four small, non-commercial poultry flocks, a game bird farm and a falconry were all affected.

None of our large commercial poultry operations became infected, but they still suffered as a result of the actions required in response to the infected flocks. The ability of the commercial operations to export poultry and poultry products was hampered. In one case, tens of thousands of day-old chicks were destroyed because Canada refused them entry after we established our first quarantine zone around two small, non-commercial flocks in Benton County.

As this illustrates, all poultry owners in Washington are part of the poultry industry, and disease in even small flocks can directly or indirectly affect flocks large and small throughout the state. It is vital that all poultry owners recognize this and take the steps to protect their birds and others, too.

The cases of avian influenza in Washington and neighboring states in the fall were the tip of what turned out to be an iceberg of historic proportions, as highly pathogenic avian influenza found its way into commercial turkey and layer operations in the Midwest, creating a massive animal disease outbreak and control response. Federal costs alone are expected to reach a billion dollars while the disease and depopulation led to the loss of more than 10 percent of our nation’s layer hen inventory and more than 7 percent of our turkey inventory. It will take at least two years for the poultry industry to recover and some producers will be put out of business permanently.

Risk returns with migration cycle

The risk that avian influenza will return to our state rides on the wings of migratory waterfowl that have once again begun to arrive from northern latitudes to spend the winter here. Unfortunately, these waterfowl species tend to carry avian influenza viruses with no ill effects, and can spread the disease to other susceptible birds through their droppings. Particularly vulnerable are the small hobby, exhibition, layer and organic flocks scattered all over our state, where the birds are allowed to spend significant time outside. 

Disinfectant for footgear outside
a bird flu town hall meeting.

The Animal Services Division of WSDA is trying to raise awareness of the threat HPAI poses to all poultry, and the biosecurity measures that flock owners should be putting in place to help protect their birds from the disease. Check out our updated website at agr.wa.gov/birdflu for information to help bird owners, no matter how large or small your flock.

There is no vaccine currently authorized for birds and there is no treatment for the disease, so flocks hit with HPAI must be euthanized in order to prevent the virus spreading. That is why prevention through good biosecurity is so important.

I encourage you to visit our webpage, look through the materials and formulate YOUR plan for protecting your birds this fall and winter. As ever, if you have questions or need help, you can also email ahealth@agr.wa.gov or call 800-606-3056.