Novel EHV-1 Assay Might Help Manage Disease Outbreaks
In a recent study, researchers examined whether EHV-1 antibody testing can confirm exposure in nonclinical horses during an outbreak.
By Nancy S. Loving, DCM
EquiManagement.com
December 10, 2025
Equine herpesvirus 1 (EHV-1) and equine herpesvirus myeloencephalopathy (EHM) have huge impacts on the horse industry, including losses of horses, delays or cancellations of events, and veterinary expenses. When a group of horses is exposed, it is helpful to identify at-risk animals as soon as possible and implement rigorous biosecurity practices. In a recent study, researchers at Cornell University examined whether EHV-1 antibody testing can confirm exposure in nonclinical horses during an outbreak.
Study Population
Two neurologically affected horses with PCR-confirmed EHV-1 had been admitted to the equine hospital for four days prior to quarantine, where they potentially exposed five other horses. Handlers initially did not wear personal protective equipment (PPE) because the positive horses were not displaying clinical signs of EHM. Four of the potentially exposed horses had been immunized against EHV-1 and EHV-4 within the prior seven months. The researchers monitored the exposed horses' rectal temperatures and collected nasal swab samples for EHV-1 two to six times biweekly over 29 days.
Full text: https://equimanagement.com/research-medical/novel-ehv-1-assay-might-help-manage-disease-outbreaks/
EHV-1 Positive Has Two Barns Quarantined at Tampa Bay [racetrack - FL]
Tampa Bay Downs Press Release
BloodHorse.com
December 11, 2025
Tampa Bay Downs has imposed a quarantine on barns 25 and 26 after a horse was confirmed to have the neurological form of equine herpesvirus type 1, also known as EHV-1, a contagious virus that causes equine herpes myeloencephalopathy.
The infected horse was sent Dec. 8 to the University of Florida, and no other horse on the grounds has tested positive or shown signs of having the virus, according to the racetrack.
In a notification, Tampa Bay Downs said it is taking numerous precautions for the immediate future, including not allowing any horses from the two barns to compete through Dec. 27. Workers at both barns must log in and out and wear protective footwear and clothing while they are working.
All horses on the grounds must have their temperatures taken twice daily, and temperature logs are required to be kept for each horse, which are procedures recommended by the American Association of Equine Practitioners.
2. Arizona Wild Horse Tests Positive for Vesicular Stomatitis
EDCC Health Watch
EquiManagement.com
December 11, 2025
On Dec. 9, the National Veterinary Services Laboratories detected a new VSV case by PCR on swab samples from a lesioned wild horse from the Salt River Wild Horse Management Group located in the Tonto National Forest in Maricopa County.
The Arizona Department of Agriculture has issued an Administrative Order temporarily restricting the movement of domestic livestock, including horses, into or out of the affected Lower Salt River area on public land.
The last outbreak of VSV in the U.S. occurred from May 2023 through January 2024, affecting 319 premises across California, Nevada, and Texas. VSV circulates annually between livestock and insect vectors in southern Mexico and only occasionally results in incursion to the U.S.
3. New avian flu outbreaks reported in 5 states
By Chris Dall, MA
CIDRAP News
December 10, 2025
New outbreaks of highly pathogenic avian influenza (HPAI) have been reported in five states, according to the latest update from the US Department of Agriculture's Animal and Plant Health Inspection Service (APHIS).
The hardest hit state is Indiana, where outbreaks affecting more than 15,000 birds have been reported in three commercial duck meat facilities in Elkhart, LaGrange, and Noble counties. An additional 19,400 birds have been affected in an outbreak at a poultry facility in LaGrange. The three countries border one another and are in the northeastern part of the state.
APHIS also reported an outbreak at a commercial poultry in North Dakota, and outbreaks in backyard flocks in Washington, Wyoming, and West Virginia.
HPAI detections are higher in the fall and spring, as wild birds spread the virus during migration. Over the past 30 days, 108 flocks (44 commercial and 64 backyard) have been hit by HPAI outbreaks, with 1.16 million birds affected.
Full text: https://www.cidrap.umn.edu/avian-influenza-bird-flu/new-avian-flu-outbreaks-reported-5-states
4. Keeping an eye out for Theileria
By Chevy-Lynn Vaske, K-State Extension news service
K-State beef cattle experts suggest Theileria may be spreading by more than just ticks.
Kansas State University
Beef Magazine
December 11, 2025
Kansas State University beef cattle experts are urging producers to stay alert this winter as new research reveals that Theileria, a tick-borne parasite affecting cattle across the region, may be spreading in more ways than once believed.
In a recent episode of the Beef Cattle Institute's Cattle Chat podcast*, veterinary entomologist Cassandra Olds explained how shifting transmission patterns and overlooked management habits could leave herds more vulnerable than expected - and what producers can do now to stay ahead of the disease.
[*See: https://ksubci.org/2025/12/05/guest-dr-cassandra-olds-theileria-theileria-transmission-winter-feeding-strategies/ ]
"Theileria is tick-borne but can also be spread by sucking lice, possibly stable flies, limited placental transmission and contaminated needles or equipment," Olds said. "This emphasizes the importance of single-needle use and highlights how difficult vector control can be."
Full text: https://www.beefmagazine.com/livestock-management/keeping-an-eye-out-for-theileria
5. Cargill Conducts Voluntary Recall of a Single Lot of Nutrena® Country Feeds® Cracked Corn for Livestock Due to Elevated Levels of Aflatoxin
FDA Company Announcement
December 11, 2025
MINNEAPOLIS, Minnesota (December 9, 2025) - Cargill Animal Nutrition & Health is conducting a voluntary recall of a single lot of Nutrena® Country Feeds® Cracked Corn for livestock because it may contain aflatoxin levels that exceed the Food and Drug Administration (FDA) action level for immature animals, wildlife, equines, small ruminants, and dairy animals. Livestock exposed to elevated levels of aflatoxin are at risk of several health effects which may include weight loss, reduced weight gain, reduced feed intake, decreased milk or egg production, vomiting, diarrhea, abdominal pain, immune suppression, impaired blood clotting, liver damage, jaundice, and cancerous tumors. Dairy animals can metabolize aflatoxin from feed into milk.
The recalled product was manufactured and distributed in Texas through retail stores.
Impacted product information is described in the table below. The lot code and manufacture date can be found on the bottom right-hand side of the label.
6. HPAI hits turkeys in North and South Dakota, ducks in Indiana
By Roy Graber
WATTAgNet.com
December 11, 2025
Avian influenza in North Dakota
The United States Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) reported that on December 9, the presence of HPAI was confirmed in a commercial meat turkey flock in Richland County. The flock included 19,500 turkeys.
Avian influenza in South Dakota
A commercial meat turkey flock in Kingsbury County is South Dakota's most recent instance of HPAI. That case was confirmed on December 5, and 38,700 turkeys were involved.
Avian influenza in Indiana
HPAI continues to spread in Indiana, with the latest case being confirmed on December 9. In that situation, 6,200 commercial meat ducks in Elkhart County were involved.
With this latest report, Indiana has now lost 65 commercial poultry flocks in 2025.