equine herpes myeloencephalopathy (EHM) Updates
Frankfort KY - The Kentucky Department of Agriculture / Office of State Veterinarian (KDA/OSV) has received notification regarding the confirmation of several cases of equine herpes myeloencephalopathy (EHM), the neurologic disease linked to equine herpes virus (EHV-1) in both Texas and Oklahoma. The initial EHV-1/EHM horse was detected several days after the WPRA event finished. The affected horses both attended the 2025 WPRA World Finals and Elite Barrel Race event in Waco, Texas, Nov. 5-9, 2025. The second EHV-1/EHM confirmation occurred at an Oklahoma horse event Nov. 18, 2025. Additional participants of these events have been notified by animal health officials and are being monitored. Kentucky horses were reported to have attended one or both events but currently there are no known EHV-1/EHM detections in the Commonwealth associated with these events.
The extent of this EHV-1 outbreak is not fully known. Presentation of EHV-1 in these horses has been acute with rapid progression and high clinical severity. Measures to prevent further horses from direct or indirect EHV-1 virus contact are recommended. These measures, including increased biosecurity overall, are encouraged.
KDA/OSV encourages event sponsors of high-risk horse population (barrel/rodeo horses) related events to take all necessary precautions to prevent further spread of this virus and protect equine health. Given the nature of this virus and routes of transmission, and out of an abundance of caution, KDA/OSV recommends canceling or postponing equine events utilizing high risk equine populations (rodeo/barrel horses) as the best method to protect horses from further exposure until such time as the extent of the current outbreak has been determined. Mitigating risk of disease introduction is a shared responsibility that requires commitment from exhibitors, trainers, event managers, facility operators, veterinarians, and animal health officials.
“Equine owners are encouraged to stay vigilant and monitor exposed or suspect infected animals closely,” Agriculture Commissioner Jonathon Shell said. “Based on current evaluations and the evolving situation, we highly recommend equine owners take this virus seriously and weigh potential risks when commingling equine.”
Any owners of horses that may have been in contact with horses that attended these events or horses that may have otherwise been exposed to EHM should work with their veterinary practitioner to establish appropriate monitoring and diagnostic plans. These owners are also encouraged to take the following precautions:
- When you return to your premises, isolate the horses that attended the event for at least two weeks.
- Have the temperature of returning horses monitored twice daily for at least 14 days after last known exposure. If a fever (>102.5°F) or other signs consistent with EHM develop, contact your veterinarian.
- Suspend hauling, showing, or mixing horses from the exposure group until further notice. Avoid taking exposed horses to other barns or events.
- Disinfect boots, trailers, wash-racks, cross-ties, tie-areas, tack and tack rooms, buckets, grooming tools, and any shared equipment. Use an appropriate virucidal disinfectant.
- Avoid sharing tack, halters, grooming equipment, buckets, water hoses, etc., between exposed and unexposed horses.
- When doing feeding and chores, work with the returning horses last, wear boots and coveralls, and remove them before working with your other horses.
- If any horse exhibits neurologic signs, coughing, or nasal discharge, isolate it immediately, wear protective gear, and call your veterinarian.
- Keep accurate records: track which horses were present at events, their movement, and who handled them for contact tracing if needed.
- Stay in contact with your local veterinarian and keep up to date on updates from state veterinary authorities.
- Have laboratory samples for clinical horses submitted to an American Association of Veterinary Laboratory Diagnosticians (AAVLD) accredited laboratory. (e.g. - University of Kentucky Diagnostic Laboratory (UKVDL) or Murray State University -Breathitt Veterinary Center Laboratory)
- Wash your hands.
Clinical signs of EHM in horses may include fever of 102.5°F or greater (fever most often comes before neurologic signs), nasal discharge, lack of coordination, hindquarter weakness, leaning or resting against a fence or wall to maintain balance, lethargy, urine dribbling, head tilt, diminished tail tone, and penile paralysis. It is important to remember these signs are not specific to EHM and diagnostic testing is required to confirm infection. If you suspect your horse has been exposed to EHV-1, contact your local veterinarian.
Additional resources for equine owners can be found here:
The equine industry is encouraged to obtain the latest information on equine disease events nationwide on the Equine Disease Communication Center (EDCC) website. Subsequent EHM cases related to these events will be posted on the EDCC.
Additional resources can be accessed through the sites noted below:
Federal order issued regarding dairy cattle requirement
- Veterinarians, Exhibitors, & Producers; Federal Order issued on Monday, April 29, 2024
- Mandatory Testing for Interstate Movement of Lactating Dairy Cattle
If you still have questions about animal movement after reading all of the below information, please "Call Before You Haul"--502-573-0282 (Office of State Veterinarian)
- Prior to interstate movement, lactating dairy cattle are required to receive a negative test for Influenza A virus at an approved National Animal Health Laboratory Network (NAHLN) laboratory. This test must be performed within 7 days prior to shipment. Within Kentucky, the two NAHLN labs are UKVDL(https://vdl.uky.edu/) and BVC (https://breathitt.murraystate.edu/). Exception: If moving directly to slaughter from State of origin aggregation site or facility of origin.
- Owners of herds in which dairy cattle test positive for interstate movement will be required to provide epidemiological information, including animal movement tracing. Lactating dairy cattle from herds which have tested positive for Influenza A are not eligible for interstate movement for thirty (30) days from the most recent collection of any sample that tests positive from any individual animal in the herd. After the 30-day period, animals must be tested again for movement.
- Dairy cattle moving interstate must adhere to conditions specified by APHIS. A Certificate of Veterinary Inspection
(CVI) is required for all interstate movements of dairy cattle regardless of age or sex. This includes dairy cattle coming into Kentucky from another state to a Kentucky livestock market. Check with state of destination SAHOs for any other requirements.
- Dairy Cattle coming from an affected state (Arizona, California, Colorado, Idaho, Iowa, Kansas, Michigan, Minnesota, Nevada, New Mexico, North Carolina, Ohio, Oklahoma, Oregon (detected in a hog), South Dakota, Texas, Utah, and Wyoming) must obtain an OSV issued permit prior to movement into Kentucky and permit number stated on the Interstate CVI. All cattle on the CVI must have individual official identification.
- The individual official identification must be recorded on the CVI.
- The CVI must include a statement that the cattle are both free from, and have not been exposed to, a known contagious and infectious disease.
All Dairy Cattle from Affected States (FO + Kentucky)
- CVI or Owner Shipper Statement
- Appropriate ID (OID or Backtag)
Clinical Signs of HPAI in Dairy Cattle:
- Sudden drop in feed intake
- Acute drop in milk production
- Severely affected cattle may have thickened colostrum-like milk or no milk
- Abnormal tacky or loose feces
- Lethargic, dehydrated and fever
- Respiratory signs including clear nasal discharge
- Additional variable clinical signs
- Affected cattle may be asymptomatic (subclinical)
Livestock Market Owners/Operators: Federal Order issued on Monday, April 29, 2024
Mandatory Testing for Interstate Movement of Lactating Dairy Cattle
- Prior to interstate movement, lactating dairy cattle are required to receive a negative test for Influenza A virus at an approved National Animal Health Laboratory Network (NAHLN) laboratory. This test must be performed within 7 days prior to shipment. Within Kentucky, the two NAHLN
labs are UKVDL (https://vdl.uky.edu/) and BVC (https://breathitt.murraystate.edu/). Exception: If moving directly to slaughter from State of origin aggregation site or facility of origin.
- Dairy cattle moving interstate must adhere to conditions specified by APHIS. A Certificate of Veterinary Inspection (CVI) is required for all interstate movements of dairy cattle regardless of age or sex. This includes dairy cattle coming into Kentucky from another state to a Kentucky livestock market. Check with state of destination SAHOs for any other requirements.
Dairy Cattle coming from an affected state
(California, Colorado, Idaho, Iowa, Kansas, Michigan, Minnesota, New Mexico, North Carolina, Ohio, Oklahoma, South Dakota, Texas, and Wyoming must obtain an OSV issued permit prior to movement into Kentucky and permit number stated on the Interstate CVI.
All cattle on the CVI must have individual official identification.
- The individual official identification must be recorded on the CVI.
- The CVI must include a statement that the cattle are both free from, and have not been exposed to, a known contagious and
infectious disease.
A copy of the CVI must be retained by the livestock market.
All dairy cattle at a livestock market regardless of age or sex must be officially identified prior to leaving the livestock market unless they are going to be slaughtered within 72 hours after leaving the market (they can be moved interstate on a CVI with the backtag listed as official ID for slaughter within 72 hours after leaving the livestock market).
All Dairy Cattle from Affected States (FO + Kentucky)
- CVI or Owner Shipper Statement
- Appropriate ID (OID or Backtag)
Clinical Signs of HPAI in Dairy Cattle: If Dairy cattle are exhibiting these signs/history, it is recommended that they are
not unloaded or be offered for sale. If dairy cattle are brought to livestock market from out of state without a CVI/Testing, if required, then the cattle should not be accepted for that sale.
- Sudden drop in feed intake
- Acute drop in milk production
- Severely affected cattle may have thickened colostrum-like milk or no milk
- Abnormal tacky or loose feces
- Lethargic, dehydrated and fever
- Respiratory signs including clear nasal discharge
- Additional variable clinical signs
- Affected cattle may be asymptomatic (subclinical)
DISEASE PREVENTION
The Office of the State Veterinarian is committed to protecting the health and well-being of Kentucky’s livestock and poultry. Through disease monitoring, prevention programs, and rapid response efforts, we work to safeguard animal populations, support producers, and maintain public confidence in the state’s agricultural industry.
Click here to read more on our efforts.
OFFICE OF STATE VETERINARIAN
- Protect the health and welfare of Kentucky's livestock, poultry, and agricultural industries
- Promote an environment which enhances the economic and recreational opportunities and prosperity of Kentucky agriculture
CONTACT THE USDA
- The USDA Import Number (animals coming into Kentucky from another country) is 301-851-3300. The email address is: VS.Live.Animal.Import.Export@aphis.usda.gov
- For information on exporting animals out of the country, contact USDA Veterinary Services at 502-848-2040.
- Veterinary Medicine Loan Repayment Program (VMLRP):
The VMLRP will pay up to $25,000 each year towards qualified educational loans of eligible veterinarians who agree to serve in a NIFA designated veterinarian shortage area for a period of three years.
The Kentucky Department of Agriculture's Office of State Veterinarian is requested in the early part of each year to make the shortage area nominations for the State and to designate the type of shortage (Type I, Type II, or Type III) for each area. These nominations are reviewed by the NIFA program and all or a portion of the areas will be approved and posted on the NIFA site listed above. Once the areas are designated, veterinarians make application directly to NIFA to fill one of the designated areas. There are specific deadlines for applications that are listed on the NIFA site each year.
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