The Texas Animal Health Commission has been inundated with calls on the neurological equine herpes virus, ranging from people wanting to know if they should cancel an equine event to when are updates available.
The following are definitions for EHV-1 and EHM, derived from the United States Department of Agriculture’s Animal and Plants Health Inspection Service website at www.aphis.usda.gov:
• Suspected EHV-1 case: An exposed horse with a fever – a temperature greater than 101.5 degrees Fahrenheit – during the monitoring period.
• Confirmed EHV-1 case: A suspect EHV-1 case whose infection is laboratory confirmed by virus isolation and/or polymerase chain reaction (PCR) detection of the virus, or a four-fold change in titer on the serum neutralization test using paired sera.
• Suspect EHM case: An exposed horse exhibiting signs of central nervous system (CNS) dysfunction, including most commonly posterior incoordination, weakness, recumbency with inability to rise or bladder atony.
• Confirmed EHM case: A suspect EHM case testing positive for EHV-1 by virus isolation and/or PCR assay on nasal swab or blood (buffy coat). In cases of sudden death or where the horse dies as a result of neurological complications, the postmortem lesions are consistent with those of myeloencephalopathy and EHV-1 has been isolated, detected by PCR, or demonstrated by immunohistochemical examination of the CNS.
• Non-clinical EHV-1 case: (It is not recommended to test exposed non-clinical horses). An exposed horse with no clinical signs (no fever and non-neurologic) testing positive for EHV-1 by virus isolation and/or PCR assay on nasal swab or blood (buffy coat).
Ramirez said TAHC keeps track of the official data in Texas of EHV-1 cases.
“We are the source [for the data],” she said, adding that she hopes media sources direct individuals “to get our updates and not rely on hearsay.”
She said the TAHC has not modified entry requirements into Texas and suggests individuals check with specific states on entry requirements.