There are fears of another horse flu outbreak after tests on a horse in Sydney’s west.

A horse is being tested again on Thursday to confirm whether it has the disease after earlier separate tests returned both positive and negative results.

NSW primary industries minister Ian Macdonald said there was serious concern the devastating disease was returning to Australia after the tests on the horse at the quarantine centre at Eastern Creek.

It is just over a year since an outbreak of equine influenza (EI) crippled the racing industry in NSW, Macdonald said.

“To be quite honest, I was very worried because a national standstill, particularly at this time of the year, if it had got out of Eastern Creek, would be devastating,” Macdonald told reporters in Sydney.

The news follows a recommendation by Macdonald for voluntary vaccinations of all horses in NSW.

He detailed his views this morning during a speech to a national summit of industry experts to address the management and prevention of EI.

The decision on compulsory vaccinations should be left to individual sectors within the horse industry, he said.

“Say the racing sector, that could determine its rules in terms of whether a horse is vaccinated or not in attending an event,” Macdonald said.

“Each sector would have the ability to impose its own rules.”

Last year’s EI outbreak resulted in a government review of the systems at Eastern Creek’s quarantine facility, where the disease originated and led to horses throughout NSW and in Queensland being infected.

The outbreak shut down the multi-million dollar racing industry in NSW and Queensland for three months and affected the thoroughbred breeding industry.

Macdonald said even the best procedures might not be enough to contain another outbreak.

“There’s great upgrades in place there now and, hopefully, it could be contained,” he said.

“But I believe that system failure is with us right around the world. That the best walls often are breached and maybe we need to look at other measures to ensure we never have a standstill again in the industry.”

Racing NSW chief executive Peter V’Landys said another outbreak would cripple the industry, as it did just over a year ago.

“If it’s got out again, it’s going to cost tens of millions of dollars,” V’Landys told reporters on Thursday at a national summit on EI in Sydney.

“Forty thousand people who earn a living in racing directly or indirectly out of work again.

“It will have devastating consequences.

“It was catastrophic last year and it has the potential to be catastrophic again.”