EDCC Health Watch has confirmed 44 EHV Cases associated with the Women’s Professional Rodeo Association (WPRA) World Finals and Elite Barrel Race event Nov 5-9. The cases are located in Texas, Oklahoma, Louisiana, Colorado, New Mexico, Washington, Arizona, and South Dakota. EHV-1 creates four manifestations of disease in horses, including the neurological form, respiratory disease, abortion, and neonatal death.
Biosecurity warning sign at entrance to horse farm.
Two main methods of prevention can be implemented to avoid EHV outbreaks. Vaccinations and biosecurity protection are both important in preventing EHV diseases and in reducing exposure.
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EVH-1 disease is highly contagious and is spread by direct horse-to-horse contact with nasal secretions. It may also be spread by the inhalation of infected air particles, but it is not known how far distant the airborne virus can spread under typical horse management and environmental conditions.
The disease can also be spread indirectly through contact with physical objects contaminated with the virus, such as human hands and clothing, equipment, tack, trailers, grooming equipment, contaminated feed, and water buckets.
Horses suspected of having EHV infections should be examined by a veterinarian and tested for virus shedding. Infected horses should be isolated immediately and all contact with other horses should be avoided. Exposed horses should also be isolated.
Two main methods of prevention can be implemented to avoid EHV outbreaks. Vaccinations and biosecurity protection are both important in preventing EHV diseases and in reducing exposure.
The goal of vaccination is to induce resistance to infection prior to exposure by producing a strong and durable immune response without inducing clinical signs of the disease in the horse. Several vaccines are available for protection against both respiratory disease and abortion as a result of EHV-1 infection, but currently no equine vaccine is licensed that has a label claim for protection against the neurological strain of the virus.
Biosecurity measures include doing everything possible to reduce the chances of an infectious disease being carried onto your property by people, animals, equipment, or vehicles, either accidentally or on purpose. Anything that touches an infected horse and secretions shed by sick horses have the potential to transfer pathogens to other horses.
The immediate separation and isolation of identified suspect cases is key to disease control. Ideally, a person caring for a sick horse should not also work with or be around healthy horses. If this is impractical, it is recommended that healthy horses should be worked with first and sick horses last.
Wearing disposable gloves and changing them between horses or the use of hand sanitizers between horse contacts are alternative recommendations. Thorough cleaning and disinfection of foot wear between entry into barns and stalls can also minimize risks of disease spread.
Herpes viruses are susceptible to many disinfectants, including a 1:10 dilution of bleach in water. Both alcohol and bleach disinfectants are inactivated by organic matter, so all soil and manure should be cleaned away before using these products. Soap and detergent can be used effectively before applying a disinfectant.
A disinfectant that retains activity in the presence of organic matter is recommended In barn environments where organic material cannot be completely eliminated. Phenolics, such as 1 Stoke Environ or SynPhenol-3, or accelerated hydrogen peroxide products, such as Virkon, have this property. Always follow manufacturer's recommendations when using these products.
A veterinarian should be called to make a diagnosis at the first sign of symptoms of EHV. Nasal swabs and blood samples will be collected from the symptomatic horse. Recent advancements in EHV-1 diagnostic testing enable laboratories to differentiate the non-neuropathic and the neuropathic strains of EHV-1.
Unfortunately, there is no cure for the equine herpes virus. It may remain dormant in the horse's body, re-emerge at any time, and is resistant to the horse's immune system defenses. However, there are medications, such as antibiotics, that can help with the secondary infections and symptoms the horse may suffer from.
Horses infected with the EHV-1 virus need plenty of rest and a proper, well-balanced diet, while those with the subtype affecting the respiratory system will require fresh, clean air. These horses may also require medication to break up the mucus that accumulates and clogs their airways.
Treatment is mostly supportive and includes anti-inflammatory medications, such as corticosteroids. Some horses require IV fluids if they cannot maintain their hydration. Horses should be isolated in a safe, well-bedded stall, especially if they are severely ataxic and have trouble rising. Recumbent horses may benefit from the use of a sling.
Horses that have difficulty urinating may need to be catheterized several times daily and may benefit from medication to prevent bladder infection.