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Disease Outbreak Alerts

Updates on current disease outbreaks are listed here as they occur and will include the date listed, disease name, location and current status. Specific premises will not be named but the general location by town, county and state will be listed. When locations, events or horses are at risk they will be listed. Updates will be posted as they are received.

Date Disease Location Status
February 24, 2017 Equine Herpes Viruses NV Investigation Initiated
The Nevada Department of Agriculture has received multiple reports of horses exposed to equine herpesvirus type 4 (EHV-4) and Streptococcus equi (Strangles). The state veterinarian has recommended postponing some events and may issue quarantine orders after making confirmation of diagnoses. For more information go to
February 23, 2017 Equine Herpes Viruses New Orleans, LA Quarantine Released
As of February 6, 2017, all barns were released from quarantine. As of February 15, 2017, the last horse in isolation tested negative for a second time and was released. With no more barns or horses under restrictions, the quarantine on the New Orleans Fair Grounds was removed on February 15, 2017.
February 23, 2017 Equine Herpes Viruses Denton County, TX Confirmed case(s): Quarantine
Texas Animal Health Commission (TAHC) confirmed Equine Herpes Myeloencephalopathy (EHM), the neurologic disease linked to Equine Herpes Virus (EHV-1), in a Denton County barrel racing horse on February 21, 2017. The horse showed signs of ataxia, loss of coordination of the muscles, and other neurologic signs consistent with EHM when evaluated by a local veterinarian. The premises is under quarantine and TAHC staff is working closely with the owner and veterinarian to implement testing protocols and biosecurity measures. Prior to confirmation, the positive horse attended barrel racing events at the NRS Arena in Decatur, TX on February 15 and Northside Arena in Fort Worth, TX on February 14. The TAHC has been in contact with event management and veterinarians to ensure enhanced biosecurity measures are taken on the premises and event participants are notified. While the risk of exposure to the virus was likely low at these events, owners of horses potentially exposed are encouraged to take precautions. For more information go to
February 20, 2017 Equine Herpes Viruses San Diego County, CA Outbreak Update
February 16, 2017: The confirmed quarantined Equine Herpesvirus Myeloencephalopathy (EHM) case in San Diego County is recovering. CDFA continues to monitor the situation. CDFA is aware of Equine Herpesvirus-1(EHV) circulating in horses previously stabled in Tent 21 of the HITS Thermal Show grounds. However, CDFA only has regulatory authority (ie quarantine issuance authority) over EHV-1 confirmed cases with neurologic signs (Equine Herpesvirus Myeloencephalopathy.) CDFA recommends exhibitors at the HITS Thermal Show follow enhanced biosecurity protocols.
February 17, 2017 Equine Herpes Viruses Durham Region, ON Confirmed case(s): Quarantine
The Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) has been notified of two confirmed cases of Equine Herpes Myeloencephalopathy (EHM), caused by equine herpes virus 1 (EHV-1).The horses from Durham Region were referred to the Ontario Veterinary College with neurological signs and are receiving treatment. Three other horses on the farm have tested positive for the mutated (neuropathogenic) strain of EHV-1 on nasal swabs but are not demonstrating neurological signs at this time. The farm owner has voluntarily placed the premises under a self-imposed quarantine to reduce the risk of viral spread.
February 16, 2017 Strangles Hardee County , FL Confirmed case(s): Quarantine
On February 16, one premise in Hardee County, Florida was placed under quarantine for strangles. The index case was recently imported from North Dakota in late December or early January and had mild nasal discharge at the time. The horse seemed to improve with anitbiotics but began to have nasal discharge and a swollen lymph node which cultured positive within the past week. No horses have left the facility since the horse became clinical again. This the first case for Hardee County and case 11 for Florida in 2017.
February 14, 2017 Equine Herpes Viruses San Diego County, CA Confirmed case(s): Quarantine
A 10-year old Warmblood gelding in San Diego County displaying neurologic signs of urine dribbling and hind limb ataxia was diagnosed as Equine Herpesvirus Myeloencephalopathy (EHM) based on a positive test for Equine Herpesvirus -1 by the California Animal Health and Food Safety (CAHFS) Laboratory. The neurologic signs were first noted on Tuesday February 7th. The positive horse was stabled in tent 21 at the HITS Show in Thermal, CA from January 21, 2017 to February 5th. The EHM horse and one additional exposed horse have been quarantined at their home premises in San Diego County. CDFA has been in contact with HITS show management and veterinarians to ensure enhanced biosecurity measures are taken on the premises. CDFA recommends any exposed horses be observed for clinical signs and have temperatures taken twice daily. CDFA will continue to monitor the situation. Go to:
February 10, 2017 Equine Herpes Viruses Keeneland, Lexington, KY Quarantine Released
Keeneland’s barn on Rice Road that has remained under quarantine, is today released from the quarantine and all associated restrictions. Testing of this barn’s population of horses that had been exposed to EHV1 was completed today (2/10/2017) with each horse testing NEG on both nasal swabs and whole blood. Having been greater than 14 days post exposure and each horse now having two (2) negative sets of results – The KY Office of State Veterinarian has released the quarantine imposed on January 22, 2017 and horses from this barn are under no further restrictions. With this release, we have no barns at the training center under quarantine or restriction. Previous positive horses do remain under regulatory monitoring and are quarantined at a secured segregated area off the site and will remain so until they too are confirmed negative by PCR testing. For more information go to
February 10, 2017 Equine Herpes Viruses Turfway Park, Florence, KY Quarantine Released
Results of testing from the population of horses in the quarantined barn have been reported, and with it having been greater than 14 days since the population was last exposed, the quarantine is released and horses in the barn are under no further restrictions. With this barn now released, there are no racing or training facilities in KY under quarantine for EHV1. Previously positive horses do remain under regulatory monitoring and remain quarantined in secured isolated areas. Racing at Turfway continues uninterrupted. Trainers shipping in to race or train will continue to be assigned stabling in the receiving barns unless the individual trainer has stalls permanently assigned on the backside. All horses entering the stabling area are required to present valid certificates (EIA and CVI) qualifying the horse’s entry onto the backside. The CVI must include statements that demonstrate a valid vaccination history. For more information go to
February 10, 2017 Equine Herpes Viruses Ingham County, MI Confirmed case(s): Quarantine
On February 8, 2017, a horse from a small stable in Ingham County, Michigan, was diagnosed with EHV-1. The horse had only mild clinical signs and is recovering. The farm is under quarantine until all horses are free from clinical signs, including fever, for 21 days. Horses at this farm rarely travel and there has been no recent movements, therefore there is no need for disease trace investigation work, at this time.