Hendra virus infections in horses have been occurring since first encountered and recognised in Queensland in 1994. In total at the time of writing there have been more than 87 confirmed cases in horses on 51 separate properties extending from far North Queensland to the Kempsey region of mid North Coast New South Wales. Most importantly there have been seven people who have tested positive and four of these people have died as a result of the Hendra virus infection. The disease is sporadic and apparently seasonal appearing to occur during the winter months, but has the likelihood of fatal consequences in horses and humans. Hendra virus is endemic in flying fox populations in many areas of Australia and the virus can "spillover" from flying foxes to horses and it is possible for the virus to spread from horses to people and possibly from horses to dogs. The risk of Hendra virus exposure is attributed to close proximity of horses to roosting and feeding habitats of flying foxes. Any unexplained illness in horses with known or recent contact with flying foxes must be considered as a suspect Hendra infection.

HENDRA VACCINATION

A highly protective veterinarian administered Hendra vaccine is available and involves two initial vaccinations 21-42 days apart followed by a booster at six months, and then annual boosters after that. Horses need a microchip inserted if they don't already have one before a record of vaccinations can be entered into the online registry. The vaccine is safe and effective and no vaccinated horse has contracted the disease. Any horse arrivals should be assessed for signs of illness regardless of vaccination status. Scone Equine Hospital recommends that all clients receiving horses from Queensland, north coast region of New South Wales or any area of known flying fox activity stipulate that the horses have been appropriately vaccinated with the commercial vaccine. Horses that have a verified immune vaccination status are considered low risk. More information about the vaccine and access to the registry of vaccinations can found at www.health4horses.com.au.

At present there have been no confirmed cases of Hendra virus infection in the Scone Equine Hospital practice area of the Upper Hunter Valley.

Horse owners and stud managers need to be vigilant for signs of illness in any horses recently arrived on your property and need to be aware of the horse's vaccination status. Any horses arriving from a high risk area showing signs of illness should only be handled with bio-security precautions and isolated. Care should be taken not to allow staff to come into contact with any discharge or secretion from the horse. Scone Equine Hospital recommends that all clients receiving healthy horses from Queensland, north coast region of New South Wales or any area of known flying fox activity require that the horses undergo a veterinary inspection within 24 hours prior to departure from the property of origin to declare that the horse is free of symptoms of infectious disease including Hendra virus and that the property of origin has not been the site of suspected Hendra virus case or unexplained death within the previous month. This declaration form can be downloaded from the Scone Equine Hospital website under Admission Procedures / Vet Declaration Form.

Unvaccinated horses that have been in areas that Scone Equine Hospital have defined as high risk in the previous 21 days will have additional precautions applied before treating them to ensure that we are providing a safe workplace for staff and are not potentially exposed to Hendra virus. This will apply to horses travelling directly from high risk areas and also to horses on local properties but recently arrived from a high risk zone.

Scone Equine Hospital has a policy to refuse admittance of a case if:

- the horse is not fully vaccinated for Hendra virus

- has clinical signs similar to those exhibited by past Hendra cases

- has arrived (within previous 21 days) from the area considered higher risk for Hendra

WHAT ARE THE DEFINED RISK AREAS

The areas that are defined to be high risk for Hendra virus cases are based on historical case distribution. However, Hendra virus could potentially occur whereever there are flying foxes in the same vicinity as horses. The high risk area definition will be revised if the case distribution changes. The area consists of all of Queensland and the DPI Local Lands Service (LLS) region of North Coast. The north coast region encompasses 12 local government authorities (LGA) listed below:

Tweed

Kyogle

Byron

Lismore

Ballina

Richmond Valley

Clarence Valley

Coffs Harbour

Bellingen

Nambucca

Kempsey

Port Macquarie-Hastings

CLINICAL SIGNS

The difficulty in identifying a Hendra virus infected case is that signs may be mild, variable and not easily noticed. They can include an increased temperature, lethargy, respiratory discharge or distress, neurological signs, mild colic signs or sudden death. In some cases the initial presentation in Hendra infection has been a deceased horse caught in a fence due to neurological signs and rapid deterioration. This highlights the need to always consider the possiblity of Hendra virus. Human infection has occurred when the possiblity of Hendra virus was not considered.

SEH veterinarians who are called to treat horses arriving from these higher risk areas which are showing signs of illness will consider these horses high risk until proven otherwise. This involves wearing appropriate Personal Protective Equipment with strict bio-security protocols. Vaccination status of arriving horses should be known before they enter the property.

Please assist us by notifying your veterinarian if the horse comes from a high risk area or is showing any of the symptoms. Any horse in this situation is not refused treatment and the horse's welfare is alway our priority, but any treatment will need to be provided in a safe manner on farm either by our vets or by the potentially referring vet. Admission may be delayed until Hendra virus exclusion testing is completed with negative results. There have been a few recent cases that have been refused admission to Scone Equine Hospital based on these risk factors.

Please do not hesitate to contact your veterinarian if you have any questions regarding Hendra Virus vaccination and other preventative measures.