Dr. Kent Fowler of the California Department of Food and Agriculture returned to Los Angeles April 17 to address horse owners about the Equine Herpes Virus-1 (EHV-1) , a health threat that became intimately familiar to the area after an outbreak last fall. The “all-clear” was issued months ago, but knowledge of the virus’s detection, treatment and mitigation are invaluable going forward wherever horses reside. Equine Herpes Myeloencephalopathy (EHM) is the designation given to a horse showing neurologic dysfunction caused by the EHV-1 virus.

Early Detection
When potential exposure to the virus is suspected, Dr. Fowler instructs that temperatures be taken twice daily. The temps should not be taken after the horse has been worked, as you may record an elevated temperature due to the recent exercise. Also, temperatures should not be taken immediately after the horse has received medications, as this, too, may cause an increase or decrease in body temperature for the horse. It’s important to know how to use a thermometer correctly and how to shake it down before taking a rectal temperature.

Immediate Treatment
If a horse is running a significant fever — over 101.5 degrees– call your veterinarian. Quick action can help with the severity of symptoms. EHV-1 is contagious, and the CDFA recommends immediate isolation for a febrile (feverish) horse. It limits the transmission of the virus to other horses.

Isolation.
A horse with compatible EHV-1 symptoms should be isolated immediately to a stall that is not in contact with other horses, or should be moved off the premises and isolated from other horses. Any horse that tests EHV-1 positive should be isolated immediately. The test (nasal swab and/or blood) result is reported by the lab to your veterinarian.

Enhanced Bio-Security.
This is a critical part of containing the spread of the virus. For a complete understanding and instructions go to:
https://www.cdfa.ca.gov/AHFSS/Animal_Health/

Continued monitoring of exposed horses.
In large barns, it is advised to implant a biothermal microchip in the middle third neck crest of the horse. This makes it possible to take temperatures rapidly and accurately. However, if your horse is already micro-chipped, a second microchip should not be implanted. Check with your vet.

Other facts and observations:
* A horse with neurologic dysfunction caused by the EHV-1 is classified as an EHM case. An EHM diagnosis results in a regulatory quarantine in California and many states.
* Since May of 2011, in California there has been 33 premises affected with EHM.
* Most young horses are exposed to the EHV virus. They may carry the virus for many years and recrudescence may occur in horses that are stressed, ill or aged.
* Both strains of EHV-1 (the neuropathogenic or mutant strain and the non-neuropathogenic or wild strain) can cause neurologic dysfunction in the affected horse.
* No vaccine is labeled to prevent EHM. There is controversy over the effectiveness of vaccines for EHV-1 and the interval that those vaccines should be administered. The vaccine may lessen the viral load in an affected horse and thereby create a less serious illness. The virus moves in the blood and may damage blood vessels in the spinal cord and brain. This leads to the neurologic symptoms noted in an EHM case.
* There is a need for a national testing standard for laboratories conducting EHV-1 PCR (polymerase chain reaction) testing.
* The virus is easily destroyed by alcohol, sunlight, heat or bleach.
* EHV-1 virus is not contagious to humans.

Moving forward, Dr. Fowler also pointed out that the horseshowing public needs to encourage show grounds managers to enhance their bio-security, and encourage that only healthy horses be transported to a show.

MORE ONLINE: Http://bit.ly/706A_CDFA