Practice good biosecurity to protect your horse from strangles

Dr. Amber Itle
Washington Assistant State Veterinarian 

Strangles in horses, or Streptococcus equi infections, is a contagious disease endemic in Washington, but not usually fatal. Still, it is a reportable disease, and several cases have been reported recently to the Washington State Veterinarian’s Office.

Since the end of April, there have been reports of 16 confirmed, laboratory-diagnosed cases of strangles at five locations in King, Snohomish, Chelan, Yakima, and Thurston counties.

All are being managed by private veterinarians who have imposed self-quarantine, implemented biosecurity measures, and executed testing protocols. WSDA has been in contact with those veterinarians to monitor these cases and provide support.

WSDA can write quarantines to stop the movement of horses in cases where barns don’t comply with the instructions of a private veterinarian, but that has not been necessary in any of these recent cases because all are complying with their self-imposed quarantines.

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 disease.

Strangles is rarely fatal and the prognosis for recovery is usually very good with proper care. But as the name suggests, strangles can affect a horse’s respiratory system. 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.

EHV-1 detected in horse at equine facility, quarantine order issued

Dr. Brian Joseph
Washington State Veterinarian

The Washington State Department of Agriculture (WSDA) has quarantined a facility in King County after a single laboratory-verified case of equine herpes virus EHV-1, neuropathogenic strain, was detected there.

On April 5, a horse at the Gold Creek Equine Facility in Woodinville tested positive for EHV-1. The horse has been moved to an isolated area on the premises and WSDA has quarantined the facility. Temperatures of the horses at the facility will be taken twice daily.

Gold Creek has cooperated fully with the quarantine order and operators there are working to ensure strict biosecurity measures are in place. WSDA is tracing movements of horses off the premises prior to the quarantine and may issue additional quarantine orders if needed.

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.

More information about testing, vaccines and biosecurity can be found in our previous blog about EHV-1.  This is a developing situation. We will update this blog as we learn more.

4/9/18 UPDATE: 

As a precautionary measure, on April 6 WSDA issued quarantine orders for two additional locations in Snohomish County where horses from Gold Creek had been transported prior to WSDA issuing the initial quarantine. The additional locations include a stable in Snohomish and a private residence in Monroe.

Horses at these additional sites are being monitored by veterinarians, but none have shown any signs of illness. All three sites are cooperating with the quarantine orders and are working to ensure strict biosecurity measures are in place.

4/26/18 UPDATE: 

The quarantine at Gold Creek remains in place although no other horses have tested positive or displayed neurological signs. The quarantine will remain until the infected horse, has had two negative tests for EHV-1 (the horse has had one negative swab since the initial detection and is awaiting a second negative test for confirmation.)

The quarantines on the other two facilities have been lifted as no horses tested positive or displayed symptoms.

5/1/18 UPDATE:

We're happy to update that all quarantines have now been lifted, including the quarantine at Gold Creek Equestrian. The horse that initially tested positive at Gold Creek has subsequently had two negative tests and is expected to make a full recovery. No other horses, at Gold Creek or the other two facilities that were quarantined, have tested positive or showed signs of EHV-1. Many thanks to all of these facilities for their excellent response in keeping this detection contained and protecting animal health!

Quarantine lifted at Woodinville equestrian center

Dr. Brian Joseph
Washington State Veterinarian

A quarantine that has been in place at a Woodinville equestrian center since Dec. 13 was removed today following tests showing no new evidence of the highly contagious neuropathogenic strain of equine herpes virus (EHV-1).

The stable’s veterinarians deserve praise for quickly alerting WSDA of the outbreak last December, working cooperatively in protecting the horses and communicating difficult decisions to the stable's owners.

It also helped that the owners were exceptionally cooperative with our oversight. Their efforts prevented this situation from becoming an outbreak at additional horse facilities.

This incident is a reminder for all horse owners to continue practicing good biosecurity at their stables and keep an eye on their horses for signs of possible infection such as high fevers, discharge from their eyes or nose, or swelling in their limbs. Owners should also look for neurological signs such as an unsteady gait, weakness, urine dripping, lack of tail tone and recumbency.

Notify your veterinarian if you detect any of these symptoms.

Our earlier article from December on EHV-1 has additional advice for horse owners concerning equine herpes.

King County horse barn quarantined for equine herpes virus

Dr. Brian Joseph
Washington State Veterinarian


On Monday, WSDA placed a King County equine premises under quarantine after a case of equine herpes, or EHV-1, was detected in a horse at the facility. However, this is a different strain of EHV-1 than the virus strain that lead to an earlier quarantine at a separate horse facility in Woodinville this past December. The two cases are not related.

The most recent case involves a non-neuropathogenic strain of equine herpes virus, though it is still serious and can cause respiratory problems in horses. The detection was made in a gelding that had recently been transported from Oregon. It is recovering under treatment and has not shown clinical signs of illness. 

In addition to placing the facility under quarantine, WSDA is working with local veterinarians actively monitoring the other animals at the facility that have been exposed to the infected horse. 

The earlier case at the Woodinville facility involved a neuropathogenic strain of EHV-1. That detection resulted in a quarantine of the facility and the need to euthanize seven horses. WSDA has not yet lifted the quarantine. 

Horse owners should take precautions to protect their animals against these contagious diseases by practicing strict biosecurity. You should also monitor your horses for signs of illness, monitor their temperature twice a day and notify your veterinarian immediately if you have any concerns.


More recommendations for horse owners to guard against equine herpes are included in a previous WSDA blog article.