In the last 9 year Hendra has been diagnosed in more than 80 horses and in 7 humans. All horses have either died or been euthanized and 4 out of the 7 humans have died.
Hendra has not been diagnosed in the Inverell district yet, but with the recent influx of flying foxes horse owners should be vigilant.
Flying foxes (fruit bats) are the natural hosts of Hendra virus. Bats themselves are not known to be affected by Hendra virus and antibodies have been found in bats as far south as Victoria and the Adelaide Hills in South Australia.
Image: Current known distribution of flying fox species that can carry Hendra virus
Horses become infected by ingesting saliva, urine, faecal or birthing material from carrier flying foxes or from contact with infected horses excreting the virus. Humans cannot contract Hendra viruses from bats; rather humans contract Hendra virus from direct exposure to body fluids of infected horses.
Clinical sign of Hendra virus
Hendra can presenting many different ways and the symptomas can initially be vague and mild and mistaken for other disease.
Common clinical signs include
- acute onset
- elevated body temperature
- increased heart rate
- discomfort, shifting weight between legs
- rapid deterioration
other signs that may be seen include: respiratory distress, neurological signs, sudden death, colic
As part of the prevention of Hendra virus, a vaccine (Equivac HeV) for horses has been developed and was released on 1st November 2012. Equivac HeV now provides a way to help break the cycle of transmission of Hendra from flying fox to horses and then to people. Horses over the age of 4 month can be vaccinated. At this stage the vaccine is not registered for pregnant mares.
Hendra vaccination protocol
- Initial: 2 doses, 3-6 weeks apart.
- Booster: 6 months from 2nd vaccine
- Annual Booster thereafter
Equivac HeV needs to be administered by an accredited vets and the horse identified by microchip.
No vaccine is 100% and strict biosecurity is essential for any sick horse. In addition to the vaccine other ways of reducing the risk of your horses contracting Hendra virus include keeping feed and water under cover, keeping horses in enclosures or paddocks with no trees at night, avoid grazing paddocks with trees where flying foxes have been nesting in.
Another disease to be mindful of is Lyssavirus, which can be transferred from bats directly to humans via bites and scratches. It causes serious illness in humans and therefore avoid any contact with flying foxes.
Equivac HeV, and its acitve constituent are not registered. An application for registration/approval of the product and active constituent has been submitted to APVMA.