Commonground
Senior Moderator
[emphasis is mine]
11/19/2025
Veterinarians, cooperative extension staff, equine industry stakeholders, and allied industry professionals,
On the afternoon of 11/18/2025, the Office of the State Veterinarian, Arizona Department of Agriculture (AZDA)
was notified by the Texas Animal Health Commission of several cases of Equine Herpes Myeloencephalopathy
(EHM) involving horses that had competed at an event at Waco, TX between 11/5-11/9 and two other
subsequent events in Guthrie, OK and Stephenville, TX. Many of these horses had since dispersed back to their
home states or have been hospitalized in adjacent states because referral hospitals have exceeded the capacity
of their isolation stall facilities. To date, no cases of equine neurologic disease associated with these recent
shows have been reported in Arizona and veterinarians are lawfully required to report within 4 hours any
confirmation of or suspicion of an EHM case.
Unfortunately, the opportunity to quarantine febrile horses at those events in TX and OK 10-14 days ago could
not be leveraged so we must now mitigate risk to the best of our collective abilities here and now. The Office of
the State Veterinarian is implementing the following movement restrictions effective 11/20/2025:
1. Interstate Certificates of Veterinary Inspection (ICVI) which would normally be valid for 30 days will now
only be valid for 5 days if the origin state has had an EHM / Equine Herpes Virus-1 (EHV-1) detection in
the previous 30 days. Those seeking to import horses into Arizona should consult with their State
Animal Health Official (origin state) to determine if their state has confirmed cases or not.
2. Concurrently, all ICVI’s will also require the following supplemental statements:
a. The equids examined and represented on this certificate have no signs of respiratory disease,
fever or any other clinical signs that may be consistent with EHV.
b. The equids referenced on this certificate do not originate from a facility currently subject to
movement restrictions due to EHV investigation or that would be considered dangerous
contacts to potentially exposed or infected horses within the previous 21 days.
3. All current Extended Equine Certificates of Veterinary Inspection (EECVI) are cancelled and EECVI
availability will be paused for the next 30 days at which time the EHV situation will be re-evaluated. In
the interim, ICVI’s needed for movement purposes will be required as described above for importation
www.agriculture.az.govinto Arizona. For Arizona origin equine exports going to other states, please contact the respective
destination State Animal Health Official for current import requirements.
To date, there have been no EHV detections or reports of sick horses in Arizona epidemiologically linked to the
previously mentioned events in Waco and Stephenville, TX and Guthrie, OK. The Office of the State Veterinarian
is not mandating cancellation of equine events at this time. Out of an abundance of caution as we near the end
of what would be the typical outside range of an incubation period (up to 14 days) following exposure at an
equine event, the State Veterinarian would encourage a voluntary postponement and rescheduling of organized
equine activities for an additional minimum of 2 weeks to provide that buffer while we wait to see if dangerous
contact horses become symptomatic.
Should organizers be absolutely compelled to press on with holding events, the grounds biosecurity, risk
mitigation, and contingency planning should include fully developed protocols for quarantine of horses that
begin to display illness during the event. These protocols should define criteria that are being monitored by
attendees (rectal temperatures twice daily on all horses >> fever if temperature is > 101.5 F) during the event for
early detection of sick horses, and facilities to house these horses on-site in remote, open-air isolation stalls or
temporary corrals placed to segregate these sick horses 120’ away from the general population. These horses
should be fed, watered, and mucked last by dedicated persons that do not handle similar duties in the general
population without thorough disinfection. Above all, once these horses have been placed in isolation and the
attending or show veterinarian has finished their evaluation, any suspicion of EHV-1 or EHM should be reported
as soon as possible and no later than 4 hours after initial assessment to the Office of the State Veterinarian.
The Arizona Department of Agriculture is currently working through attendee lists of the events in TX and OK
and will be reaching out to those individuals who have since returned to the state to ensure that proper risk
mitigation, health monitoring, and dangerous contact quarantine protocols are enacted and reporting to the
State Veterinarian is followed.
This isn’t the first time Arizona has had to deal with EHV-1/EHM risks and it certainly won’t be the last time
circumstances are thrust upon our state to deal with potential disease issues impactful to a significant portion of
the equine sector. Most owners will prioritize the health and safety of their horses and those of other equine
community members by making the right choices in avoiding unnecessary risk, to be responsible and compliant
with state and event entry requirements, to maintain a robust herd health and wellness program in their stable,
and to recognize when their horses are showing the subtlest signs of illness and take the initiative to scratch that
event for long term success.
Thank you all for your collective continued efforts in this response, remain diligent, and we will manage our way through this.
Sincerely,
Ryan Wolker DVM, MVetSc, DACVS
State Veterinarian, FADD
Animal Services Division
Arizona Department of Agriculture
https://agriculture.az.gov/sites/de...lor-NEW LOGO-MOVEMENT RESTRICTIONS-SIGNED.pdf
11/19/2025
Veterinarians, cooperative extension staff, equine industry stakeholders, and allied industry professionals,
On the afternoon of 11/18/2025, the Office of the State Veterinarian, Arizona Department of Agriculture (AZDA)
was notified by the Texas Animal Health Commission of several cases of Equine Herpes Myeloencephalopathy
(EHM) involving horses that had competed at an event at Waco, TX between 11/5-11/9 and two other
subsequent events in Guthrie, OK and Stephenville, TX. Many of these horses had since dispersed back to their
home states or have been hospitalized in adjacent states because referral hospitals have exceeded the capacity
of their isolation stall facilities. To date, no cases of equine neurologic disease associated with these recent
shows have been reported in Arizona and veterinarians are lawfully required to report within 4 hours any
confirmation of or suspicion of an EHM case.
Unfortunately, the opportunity to quarantine febrile horses at those events in TX and OK 10-14 days ago could
not be leveraged so we must now mitigate risk to the best of our collective abilities here and now. The Office of
the State Veterinarian is implementing the following movement restrictions effective 11/20/2025:
1. Interstate Certificates of Veterinary Inspection (ICVI) which would normally be valid for 30 days will now
only be valid for 5 days if the origin state has had an EHM / Equine Herpes Virus-1 (EHV-1) detection in
the previous 30 days. Those seeking to import horses into Arizona should consult with their State
Animal Health Official (origin state) to determine if their state has confirmed cases or not.
2. Concurrently, all ICVI’s will also require the following supplemental statements:
a. The equids examined and represented on this certificate have no signs of respiratory disease,
fever or any other clinical signs that may be consistent with EHV.
b. The equids referenced on this certificate do not originate from a facility currently subject to
movement restrictions due to EHV investigation or that would be considered dangerous
contacts to potentially exposed or infected horses within the previous 21 days.
3. All current Extended Equine Certificates of Veterinary Inspection (EECVI) are cancelled and EECVI
availability will be paused for the next 30 days at which time the EHV situation will be re-evaluated. In
the interim, ICVI’s needed for movement purposes will be required as described above for importation
www.agriculture.az.govinto Arizona. For Arizona origin equine exports going to other states, please contact the respective
destination State Animal Health Official for current import requirements.
To date, there have been no EHV detections or reports of sick horses in Arizona epidemiologically linked to the
previously mentioned events in Waco and Stephenville, TX and Guthrie, OK. The Office of the State Veterinarian
is not mandating cancellation of equine events at this time. Out of an abundance of caution as we near the end
of what would be the typical outside range of an incubation period (up to 14 days) following exposure at an
equine event, the State Veterinarian would encourage a voluntary postponement and rescheduling of organized
equine activities for an additional minimum of 2 weeks to provide that buffer while we wait to see if dangerous
contact horses become symptomatic.
Should organizers be absolutely compelled to press on with holding events, the grounds biosecurity, risk
mitigation, and contingency planning should include fully developed protocols for quarantine of horses that
begin to display illness during the event. These protocols should define criteria that are being monitored by
attendees (rectal temperatures twice daily on all horses >> fever if temperature is > 101.5 F) during the event for
early detection of sick horses, and facilities to house these horses on-site in remote, open-air isolation stalls or
temporary corrals placed to segregate these sick horses 120’ away from the general population. These horses
should be fed, watered, and mucked last by dedicated persons that do not handle similar duties in the general
population without thorough disinfection. Above all, once these horses have been placed in isolation and the
attending or show veterinarian has finished their evaluation, any suspicion of EHV-1 or EHM should be reported
as soon as possible and no later than 4 hours after initial assessment to the Office of the State Veterinarian.
The Arizona Department of Agriculture is currently working through attendee lists of the events in TX and OK
and will be reaching out to those individuals who have since returned to the state to ensure that proper risk
mitigation, health monitoring, and dangerous contact quarantine protocols are enacted and reporting to the
State Veterinarian is followed.
This isn’t the first time Arizona has had to deal with EHV-1/EHM risks and it certainly won’t be the last time
circumstances are thrust upon our state to deal with potential disease issues impactful to a significant portion of
the equine sector. Most owners will prioritize the health and safety of their horses and those of other equine
community members by making the right choices in avoiding unnecessary risk, to be responsible and compliant
with state and event entry requirements, to maintain a robust herd health and wellness program in their stable,
and to recognize when their horses are showing the subtlest signs of illness and take the initiative to scratch that
event for long term success.
Thank you all for your collective continued efforts in this response, remain diligent, and we will manage our way through this.
Sincerely,
Ryan Wolker DVM, MVetSc, DACVS
State Veterinarian, FADD
Animal Services Division
Arizona Department of Agriculture
https://agriculture.az.gov/sites/de...lor-NEW LOGO-MOVEMENT RESTRICTIONS-SIGNED.pdf
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