Quarantined horses cleared of equine flu

Weekend tests on 10 American horses at a New Zealand quarantine facility have found they do not have equine influenza, biosecurity officials said today.

DNA testing of samples from the horses, which had tested positive for equine influenza, indicated the results were "false positives", Biosecurity New Zealand spokesman Clive Gower-Collins said.

The horses were imported from the United States on March 23 after testing negative for the disease - but they tested positive five days after arrival in New Zealand, with the results becoming available at the end of March.

The Karaka site where the horses were being quarantined was locked down as a precaution on Friday, with no horses allowed to leave or enter the site, and no visitors allowed.

"The whole testing regime is based on an early warning principle... The first set of tests could probably be described as veracity tests - they're the ones that say you think you've got a reason for concern," Mr Gower-Collins told Radio New Zealand today.

"At that point, we began to get some anomalous test results that made our folks scratch their heads a bit. Further testing started to reveal that most certainly whatever we're dealing with here, it's not an equine illness."

Mr Gower-Collins, MAF's import standards group manager, said the 10 horses at the centre of the scare were in "robust good health".

He said earlier that it took very little to skew the results on such a sensitive test - "we may have had contamination from somebody with a cold in the lab".

The test results were crucial because an equine influenza outbreak would put at risk New Zealand's place as the only significant horse-racing nation free of equine flu.

Australia has just wrapped up an inquiry into its own billion-dollar outbreak last year when equine influenza first detected in August spread quickly among horses in New South Wales and Queensland states.

Horse movements were stopped, and some Australian racing halted at a cost estimated at $A1 billion ($NZ1.17 million).

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