EHV-1 Updates
Colorado Update
The Colorado Department of Agriculture continues to investigate the spread of Equine Herpesvirus (EHV-1) in the state.
As of 5/19/2011, 1pm:
- 8 confirmed cases of horses with EHV-1
- Two horses, which tested positive for EHV-1, were euthanized after showing severe neurological signs associated with the disease.
- 22 suspect cases. Suspect cases are those horses that are believed to have been exposed to EHV-1 but confirmatory tests are still pending.
- 10 quarantine and hold orders have been issued in 6 counties (Bent, Boulder, Larimer, Mesa, Morgan & Weld)
Colorado State Fair Horse Shows Cancelled
Colorado State Fair organizers have voluntarily cancelled three equine events following the spread of EHV-1.
- Zamora Roping originally scheduled for May 20-22, 2011. Reschedule date pending.
- Mounted Shooting Regional originally scheduled May 27-30, 2011. Rescheduled for October 7-10, 2011
- Sagebrush Slide Cow Horse Show originally scheduled June 1-5, 2011. Rescheduled for August 10-14, 2011
“We decided to reschedule these events to limit the number of horses traveling to and from our fairgrounds,” said State Fair General Manager Chris Wiseman. “Our horse shows are important to the Fair and to Colorado as a whole and we want to be proactive in protecting our horse community.”
Facts about EHV-1 Vaccines
The common vaccines available for EHV-1 immunization do not protect against the neurological form of EHV-1 disease which is commonly called equine herpesvirus myeloencephalopathy (EHM). These immunizations do protect against the respiratory and abortion forms of the disease.
The EHV-1 vaccines are thought to reduce the shedding of the virus and may decrease the amount of circulating virus in the system of infected horses. So vaccinations prior to infection may help reduce the severity of an outbreak.
In the face of an EHV-1 outbreak, the value of vaccinating EHV-1 affected horses or exposed horses is questionable and may be detrimental to the horse. When an EHV-1 outbreak occurs, it may be helpful to give an EHV-1 booster immunization in a previously vaccinated, unexposed horse.
Consult with your veterinarian to determine the best vaccination and treatment strategy for your horses in your particular situation.
BACKGROUND
New Travel Requirements for Horses Entering Colorado
Standard requirements for horses entering Colorado include a health certificate issued within 30 days of their arrival and a negative Coggins test within 12 months. The new requirement consists of a permit to enter the state. Horse owners who wish to bring their horse into Colorado must first call their veterinarian. That veterinarian can then contact the Colorado Department of Agriculture’s State Veterinarian’s Office at (303) 239-4161 and request a permit number. That number would then be included on the health certificate.
Additional Travel Tips for Horse Owners Traveling To or From Colorado
1. Contact the State Veterinarian’s Office of the destination state to find out if travel requirements have changed for that state.
2. Call organizers of the event to see if they have new health requirements or if it has been cancelled.
3. If traveling, practice appropriate biosecurity measures. Biosecurity tips may be found at www.colorado.gov/ag.
4. Isolate any new animals and those returning to the home premises for three weeks when possible.
5. Use separate water, feed supplies and equipment.
6. Continue to monitor the CDA webpage at www.colorado.gov/ag for further information to aid in the decision making for transporting horses.
If your horse attended the Ogden, Utah event:
CDA encourages all horse owners who attended the Ogden, UT, to notify their veterinarian and isolate and monitor their horses for clinical signs of the disease. These horses should have their temperature taken twice a day. Horses with elevated temperature can be sampled by a veterinarian to analyze whether their horse is shedding EHV-1. Individual horse and barn bio-security is very important. Some horses may not show signs of the disease but may still be a carrier. Those owners are also encouraged to restrict movement of their horses.
General Disease Information
EHV-1 is not transmissible to people; it can be a serious equine disease that can cause respiratory and neurological clinical signs; it can even result in death. The most common way for EHV-1 to spread is by direct horse-to-horse contact. It can also be spread by contaminated tack, equipment, and people’s clothing. In addition, the virus can be spread through aerosols (airborne) for a limited distance.
Symptoms include fever, decreased coordination, nasal discharge, urine dribbling, loss of tail tone, hind limb weakness, leaning against a wall or fence to maintain balance, lethargy, and the inability to rise. While there is no cure, the symptoms of the disease may be treatable. Horse owners should isolate any sick horses and immediately contact their veterinarian. Any individual horse with clinical signs consistent with neurological EHV-1 infection should be removed immediately from the area and placed in a separate enclosure for isolation.
Additional resources can be found at www.colorado.gov/ag.
May 19, 2011
TEXAS UPDATED
Texas Animal Health Commission (TAHC) officials are continuing to trace exposed horses that attended the National Cutting Horse Association (NCHA) Western National Championships event that ended on May 8 in Ogden, Utah. There are currently 26 known horses in Texas that attended the event. Those 26 horses and a total of 323 more cohorts (stablemates) of the 26 are currently being held under movement restrictions across the state.
Texas has currently only detected one confirmed case. That horse sought treatment at a veterinary clinic in far West Texas and has subsequently returned to New Mexico where it originated. A second horse located in Jack County has been classified as “suspect” and is pending further diagnostic testing. The TAHC is following the U.S.D.A. guidelines for clinical and suspect cases which have very specific criteria to meet the case definition, and for now suspect and confirmed cases will be the two types of cases reported.
The epidemiological investigation of all 300+ plus horses that reportedly attended the event continues nationwide, and the number of Texas horses identified as exposed may increase in the following days. Although mandatory cancellation of future events is not anticipated, the TAHC suggests that horse owners consider the risk of participating in upcoming events scheduled for this weekend and/or co-mingling their horses with other horses and equipment (trailers) of unknown history. Because the incubation period is usually about 4-6 days or less, even a one week voluntary stop movement may be enough to nip the cycle of transmission between horses before it grows in scope. Horse owners should contact event organizers in advance to ensure that scheduled events have not been cancelled. Some other states have established emergency rules for entry as a result of this situation, so if interstate travel is planned, owners and/or veterinarians writing health certificates should check in advance to ensure they meet all entry requirements. Finally, it is recommended that all newly purchased horses or introduced horses to a premise should be isolated to help prevent the accidental introduction of EHV-1 (and other diseases) onto the premise.
In related news, the NCHA has cancelled the 2011 Breeder’s Invitational.
Here is the press release from the NCHA:
In a unanimous decision, the Breeder’s Invitational (BI) Board of Directors permanently cancelled its 2011 event in the wake of the outbreak of EHV1. Earlier in the week, the show was postponed after confirmed cases of EHV1 were reported in horses that had attended the National Cutting Horse Association’s Western Nationals in Ogden, Utah. BI Officials were concerned the congregation of the large number of entries expected at the 2011 Breeder’s Invitational event had the potential of further spreading this dangerous virus.
“We did not feel comfortable with the potential of exposing horses arriving in Tulsa to EHV,” said BI Board Chairman, Jeffrey Matthews. “An outbreak at an event of this size could be devastating. The Board of Directors decided to take a conservative approach to the situation in the interest of protecting the health of the horses.”
Today, the decision was made by the Board of Directors to permanently cancel this year’s event, instead of rescheduling it to a later date this calendar year. “There is no date available in 2011 at the Expo Square that we could made work,” reported Bob O’Bannon, BI Executive Director. “And the Board was in complete agreement that they did not want to hold the event anywhere else.”
Matthews elaborated on the decision: “We have a contract with the City of Tulsa and we value that contract and our relationship with Tulsa. In the very near future, we intend to announce our plans with regard to the refund of 2011 entry fees and the reallocation of this year’s purse money, which will go toward making next year’s event even stronger.”
May 18, 2011
Oklahoma
We are getting reports that one horse in Love County in southern Oklahoma has EVI-1. NOTE: The state of Oklahoma has not officially confirmed this case.
California
In a release issued on May 17, 2011, by the California Department of Food and Agriculture (CDFA), it was reported that Equine Herpes Myeloencephalopathy (EHM), caused by Equine Herpes Virus (EHV-1), has been confirmed in 10 horses in California. Affected counties are Kern, Placer, Stanislaus, Amador and Napa. One horse in Kern County was euthanized after showing severe neurologic signs often associated with the disease. All of the infected horses recently attended the NCHA Western Nationals in Odgen, Utah, held April 30-May 8, 2011, where they were most likely exposed to the virus.
All California horses that have been in contact with an infected horse and show signs of disease or test positive for EHM will be placed under a CDFA quarantine in order to limit spread. This disease outbreak is evolving and CDFA will continue to investigate cases and provide updated information.
The CDFA has contacted all 54 exhibitors from California who participated in the Odgen event and asked them to isolate and monitor their horses for clinical signs of EHV-1. A rectal temperature in excess of 102F commonly precedes other clinical signs. Therefore, horse owners with potentially exposed horses are urged to take temperatures on each individual horse twice a day. If a temperature above 102F is detected, the horse’s private veterinarian should be contacted immediately for evaluation and laboratory testing.
While the true extent of this disease outbreak is uncertain, there is clearly a very significant elevated risk of EHM cases at this time. At this time control of the outbreak is critically dependent on biosecurity.
Arizona
While no horses at the South Buckeye Equestrian & Events Center in Buckeye, Arizona had shown clinical signs of the EHV-1 as of May 17, facility managers issued this statement yesterday, “We feel it’s absolutely necessary and our responsibility to the equestrian community to be proactive in our effort to contain this highly contagious disease. Therefore, NO horses will be accepted onto our facility beginning today May 17 until further notified.”
Colorado (UPDATED)
6 confirmed cases of horses with EVH-1
Five of the confirmed EHV-1 positive horses had recently attended the National Cutting Horse Association’s Western National Championships in Ogden, Utah.
One of the horses diagnosed with EHV-1 received the infection through contact with horses that attended the Utah event.
One horse, which tested positive for EHV-1, was euthanized after showing severe neurological signs associated with the disease. A second horse was euthanized with similar symptoms but test results have not been confirmed at this point. The others are currently under treatment by veterinarians and in biosecure locations.
14 suspect cases. Suspect cases are those horses that are believed to have been exposed to EHV-1 but confirmatory tests are still pending.
9 quarantine and hold orders have been issued in 4 counties (Boulder, Larimer, Mesa, & Weld)
UPDATE: Camelids
Camelids, which are alpacas, llamas and camels, are susceptible to EHV-1. There have been no cases of EHV-1 cases in camelids related to this spread and there are no travel restrictions. The main animals at risk for EHV-1 are those horses that traveled to Ogden, UT. Therefore, CDA believes camelids are low risk for this disease spread.UPDATE: Colorado State University Veterinary Teaching Hospital
The equine section at Colorado State University Veterinary Teaching Hospital (CSUVTH) is accepting emergency patients and is not and has not been under quarantine due to the outbreak of equine herpesvirus. The CSUVTH has remained open to emergency equine and camelid patients during the outbreak, as well as to all other animal patients. Horses brought into the hospital are routinely and carefully screened for symptoms and history of possible exposure to the disease. Any horse that may have been exposed to the virus is being held in a separate isolation unit away from the main equine section and other equine patients that are coming and going. The isolation unit where horses that may have been exposed to the disease are treated is specifically designed for treating infectious disease cases, such as EHV-1 cases. The unit is not physically connected to the main hospital or equine section of the hospital and horses in the main hospital are not exposed to horses in the isolation unit.BACKGROUND:
New Travel Requirements for Horses Entering Colorado
Standard requirements for horses entering Colorado include a health certificate issued within 30 days of their arrival and a negative Coggins test within 12 months. The new requirement consists of a permit to enter the state. Horse owners who wish to bring their horse into Colorado must first call their veterinarian. That veterinarian can then contact the Colorado Department of Agriculture’s State Veterinarian’s Office at (303) 239-4161 and request a permit number. That number would then be included on the health certificate.Additional Travel Tips for Horse Owners Traveling To or From Colorado
1. Contact the State Veterinarian’s Office of the destination state to find out if travel requirements have changed for that state.
2. Call organizers of the event to see if they have new health requirements or if it has been cancelled.
3. If traveling, practice appropriate biosecurity measures. Biosecurity tips may be found at www.colorado.gov/ag <http://www.colorado.gov/ag> .
4. Isolate any new animals and those returning to the home premises for three weeks when possible.5. Use separate water, feed supplies and equipment.
6. Continue to monitor the CDA webpage at www.colorado.gov/ag < http://www.colorado.gov/ag> for further information to aid in the decision making for transporting horses.
If your horse attended the Ogden, Utah event:
CDA encourages all horse owners who attended the Ogden, UT, even to notify their veterinarian and isolate and monitor their horses for clinical signs of the disease. These horses should have their temperature taken twice a day. Horses with elevated temperature can be sampled by a veterinarian to analyze whether their horse is shedding EHV-1. Individual horse and barn bio-security is very important. Some horses may not show signs of the disease but may still be a carrier. Those owners are also encouraged to restrict movement of their horses.General Disease Information
EHV-1 is not transmissible to people; it can be a serious equine disease that can cause respiratory and neurological clinical signs; it can even result in death. The most common way for EHV-1 to spread is by direct horse-to-horse contact. It can also be spread by contaminated tack, equipment, and people’s clothing. In addition, the virus can be spread through aerosols (airborne) for a limited distance.Symptoms include fever, decreased coordination, nasal discharge, urine dribbling, loss of tail tone, hind limb weakness, leaning against a wall or fence to maintain balance, lethargy, and the inability to rise. While there is no cure, the symptoms of the disease may be treatable.
Horse owners should isolate any sick horses and immediately contact their veterinarian. Any individual horse with clinical signs consistent with neurological EHV-1 infection should be removed immediately from the area and placed in a separate enclosure for isolation.
Additional Resources—The following information is also posted on our website at www.colorado.gov/ag <http://www.colorado.gov/ag> :
- A Guide To Understanding the Neurologic Form of EHV Infection <http://www.aphis.usda.gov/vs/nahss/equine/ehv/equine_herpesvirus_brochure_2009.pdf>
- USDA Animal Plant Health Inspection Service Resources <http://wwwaphis.usda.gov/vs/nahss/equine/ehv/>
- American Assoc. of Equine Practitioners Fact Sheet <http://www.aaep.org/pdfs/control_guidelines/Equine%20Herpes%20Virus.pdf>
- CSU EVH-1 Fact Sheet <http://www.colorado.gov/cs/Satellite?blobcol=urldata&blobheader=application%2Fpdf&blobkey=id&blobtable=MungoBlobs&blobwhere=1251713547267&ssbinary=true>
The Department has received numerous calls from veterinarians, horse owners and media. To help facilitate a timely response, please see the following list.
- If veterinarians or horse owners have questions about the disease, testing, or other aspects of the investigation:
- Contact your local veterinarian
- Dr. Kate Anderson, 303-239-4161, [email protected]
- Dr. Carl Heckendorf, 303-239-4161, Carl.Heckendorf@ag.state.co.us
