New Jersey Department of Agriculture

Memo

To: Veterinarians

From: Nancy E. Halpern, D.V.M., State Veterinarian

Date: October 24, 2006

Re: Horses at Monmouth Park Racetrack Shipped from Facility Currently Positive for EHV Type-1

     The New Jersey Department of Agriculture (NJDA) received confirmation today that two horses stabled at Monmouth Park Racetrack located in Oceanport, New Jersey were shipped from a Canadian training facility currently positive for Equine Herpesvirus Type-1 (EHV-1). The horses were clinically normal when they arrived at Monmouth Park on October 12, 2006, but one developed a fever on October 14; 48 hours after shipping from the training facility in Canada. The horse with clinical signs was initially treated with antibiotics and anti-inflammatory drugs and subsequently recovered 72 hours later.

     In addition, 2 horses at the Canadian facility developed neurologic signs; one horse was recumbent and was subsequently euthanized and necropsied and the second was taken to the University of Guelph for treatment on October 14th and 15th, respectively. Both horses later tested positive for EHV-1. Upon receiving confirmation of the positive horses from the Canadian facility on Sunday, October 22nd, the veterinarian responsible for treating the contact horse at Monmouth Park submitted samples to University of Kentucky Livestock Disease Diagnostic Center to test for EHV-1 infection in the two horses that were shipped from the Canadian facility on October 12th (only one of which demonstrated clinical signs of disease), and five additional horses in the same barn at Monmouth Park that have since developed a fever. None of the affected horses at Monmouth Park are demonstrating neurologic signs at this time. NJDA and Monmouth park officials are working with the veterinarian and trainer to conduct tracing of all horses and/or facilities that may have had contact with the affected horse.

     The EHV-1 organism spreads quickly from horse to horse and can cause respiratory problems especially in young horses, spontaneous abortions in pregnant mares, and the neurologic form of the virus can reach high morbidity and mortality rates. The incubation period of EHV-1 is typically 2-10 days. Clinical signs in of respiratory disease include fever, serous nasal discharge, depression, pharyngitis, cough, inappetence, and/or submandibular or retropharyngeal lymphadenopathy. In horses infected with the neurologic strain of EHV-1, clinical signs include, mild incoordination, posterior weakness/paralysis and recumbency, loss of bladder and tail function, and loss of sensation to the skin in the perineal and inguinal areas. In exceptional cases, the paralysis may progress to quadriplegia and death. Prognosis depends on severity of signs and the period of recumbency.

     There is currently no known method to reliably prevent the neurologic form of EHV-1 infection. It is recommended to maintain appropriate vaccination procedures in an attempt to reduce the incidence of the respiratory form of EHV-1 infection, which may help prevent the neurologic form. Transmission of the virus can occur via coughing or sneezing over a distance of up to 35 feet as well as by direct contact with infected horses, feed and equipment. Based on clinical signs, there is no reason to believe that there is any human health risk.

     NJDA Division of Animal Health, racing commission and racetrack officials have taken additional steps and safeguards to contain and prevent the spread of the disease. Specifically:   

• Enacting a quarantine on all facilities housing horses at Monmouth Park. This provision prohibits any horse from leaving or entering the restricted area until animal health and track officials determine that horses leaving the facility will not spread the disease.
• Monitoring exposed horses for signs of illness to ensure immediate detection.
• Requiring frequent disinfecting of the quarantined area and potential disease transmission pathways, including equipment of authorized individuals entering the restricted area to care for the horses.
• Requiring separate feed and water sources for horses in the restricted area.
• Prohibiting equipment, including tack, brushes, hoses, buckets, etc., from leaving the restricted area.

     New Jersey horses not connected to Monmouth Park or to horses that have been traced from Monmouth Park are not affected by these restrictions. However, horse owners and transporters should consider contacting officials at travel destinations to confirm that state or local officials have not implemented restrictions.

     This case of EHV-1 is a reminder to prevent the importation of this virus to New Jersey, and to limit its spread once it enters the state. Therefore, the New Jersey Department of Agriculture recommends:

• Horses entering a training facility, racetrack, show-grounds, etc. should have written verification by a licensed/accredited veterinarian of equine herpes virus vaccination as recommended by the manufacturer.
• Horses entering a training facility, racetrack, show-grounds, etc. should have a normal rectal temperature upon arrival.
• The neurological form of EHV is considered a reportable disease in New Jersey. If you have a horse exhibiting neurological signs or suspect Equine Herpes please quarantine the horse or premise immediately and call the Division of Animal Health at 609-292-3965.

Trailer interiors:

• Always clean and disinfect vehicles used for moving horses and other livestock after each use.
• Mix 1 part bleach to 10 parts water and spray over areas in which horses make contact during shipment.

Car, truck and trailer tires:

• Taking a few minutes to spray disinfectant over your tires can kill germs you’ve picked up in parking lots, on dirt roads, or in a stable or pasture area.

• Take time to clean and disinfect your shoes.
• Mix 3 parts bleach to 2 parts water and pour solution into a shallow container to dip shoes in after each shipment.
• Washing your hands with soap and water after handling horses will limit your ability to pass on germs.
• Change clothes or coveralls after handling horses from different locations.
• Wash clothes before wearing them again to handle and ship other horses.

Clean and disinfect:

• Stalls used to house horses and other livestock after each use.
• Mix 1 part bleach to 10 parts water and spray over horse contact areas.

• Taking a few minutes to spray disinfectant over your tires can kill germs you’ve picked up in parking lots, on dirt roads, or in a stable or pasture area.
• Washing your hands with soap and water after handling horses will limit your ability to pass on germs.
• Take time to clean and disinfect your shoes before contacting different groups of horses: Mix 3 parts bleach to 2 parts water and pour solution into a shallow container to dip shoes in after walking in a stable or pasture area.
• Change clothes or coveralls after handling horses from different locations.
• Before handling new groups of horses, wash clothes.

• Limit traffic of people who may have been exposed to germs elsewhere.
• Have visitors and employees follow the disinfection procedures indicated above.
• Newly acquired animals should be isolated for at least 14-30 days to ensure you don’t introduce disease to the rest of your horses. During this time, monitor the horses regularly.
• Keep show horses and race horses segregated from the rest of the horse population for at least 2 weeks after they have been off of the premises at shows, or races.

     If you have any further questions or concerns, contact NJDA - DAH at (609) 292-3965.