Hendra virus kills fifth horse

SYDNEY (AAP) - A fifth horse has succumbed to the Hendra virus and there are fears for seven more, as Queensland authorities battle an above average season of the baffling virus.
The horse from a Mount Alford property, near Boonah in the state's southeast, was euthanased on Monday after tests showed it had the bat-borne illness.
The tests also confirmed Hendra caused the death of a horse on the property on June 20.
A vet who treated that horse first thought it had colic but became suspicious when it showed signs of neurological distress.
The vet, Peter Prenzler, is now waiting for test results to find out whether he has contracted Hendra, which has killed four of the seven people who have contracted the disease since it was first detected in 1994.
The test results mean three horses from the same Mount Alford property have died of the disease, while another outbreak in southeast Queensland has claimed one horse from nearby Kerry.
A horse was also put down in northern NSW on July 1 after becoming ill, and was later found to have been infected with the virus.
Queensland chief vet Dr Rick Symons on Monday told reporters seven more horses on the Mount Alford property were at risk of Hendra, even though tests have so far been negative.
Two had been separated from the others because they came into direct contact with the Hendra-infected horses.
"We are not out of the woods with that yet," Dr Symons said.
"There's a chance that some of the seven remaining horses will have Hendra virus."
The owners of the horses were grieving, Dr Symons said.
"They love their horses and like most horse owners, to have this happen to them is very sad and we really feel for them," he said.
Dr Symons said it was an exceptional year for Hendra, and researchers were trying to work out why - including whether the floods had played a part.
Bats are more likely to excrete Hendra virus if they are stressed, and the loss of food due to the floods could be a factor.
"There are more than average this year and we are looking and researching and trying to find out why," he said.
"It could be just coincidence, or it could be ... seasonal, there could be bat factors, it could be environmental."
Chief health officer Dr Jeanette Young said Queensland Health had not identified any more people exposed to the virus.
So far the six people exposed to the sick horse at Mount Alford have tested negative, but they won't be in the clear until two more tests return negative in the next six weeks.
Dr Symons encouraged horse owners to attend an information session at Beaudesert RSL on Tuesday night, or Biosecurity Queensland offices set up in Boonah and Jimboomba.
There are no movement restrictions for properties other than the four already quarantined.
No horses have been moved out of the Mount Alford property since January.
A total of 35 horses are being monitored for symptoms.