Providing practical information to help you protect your farm from biosecurity risks

Horse flu and biosecurity – the evidence is in

May 1, 2012

EI vaccine and horseResearch into Australia’s first horse flu (equine influenza) epidemic in 2007 has shown that on-farm biosecurity measures are effective in preventing the spread of disease even when a major outbreak is already well underway.

Horse flu crippled the Australian horse industry in late 2007, affecting more than 70,000 horses on around 9000 properties. It brought horse racing and other activities in NSW and Queensland to a standstill and cost government and industry over $350 million to eradicate and recover from the outbreak.

Sydney University’s Kathrin Schemann says the research team has conducted a series of studies to better understand the spread of horse flu under Australia’s unique environmental condions.*

“In one study we investigated the factors facilitating and preventing the spread of horse flu onto horse properties,” says Kathrin. “We collected data from 100 properties that contracted horse flu and 100 properties that didn’t, then compared biosecurity practices used at infected and uninfected properties, among other factors.”

The researchers found that, at a basic level, keeping horses away from fences and using a footbath to disinfect shoes and boots upon arrival on the property helped prevent the spread of infection onto horse properties. Similarly, other hygiene measures adopted on the properties, such as hand washing and changing of clothes and shoes, were generally protective against the spread of horse flu.

“We also checked the effect of these practices after controlling for the proximity of a property to the nearest infected property, and whether or not the horses attended an event, because these factors were also a significant determinant of whether or not a property contracted horse flu,” Kathrin says. “Even after accounting for these and some other factors, using a footbath to disinfect shoes and boots upon arrival on the property was still protective against the spread of horse flu – in fact it meant an almost four-fold reduction in the likelihood of getting infected.”    

The research team is still sifting through all the data to untangle the exact effect of other biosecurity practices during the epidemic. But until then Kathrin believes that having a footbath can be assumed to be generally representative of sound biosecurity practices.

“Our study strongly suggests that complying with certain on-farm biosecurity measures prevented horses on premises in high risk areas from being infected with horse flu during the disastrous 2007 outbreak,” she adds. “On that basis I can definitely recommend that horse owners and property managers adopt on-farm biosecurity practices, as well as all necessary disease control measures, should another infectious disease break out in Australia.”

* Firestone S.M., Schemann K., Toribio J.-A.L.M.L., Ward M.P., Dhand N.K. (2011) A case-control study of risk factors for equine influenza spread onto horse premises during the 2007 epidemic in Australia. Preventive Veterinary Medicine 100, 53-63.

The research was conducted by Dr Simon Firestone and Kathrin Schemann under the supervision of Dr Navneet Dhand, Professor Michael Ward and Associate Professor Jenny-Ann Toribio from the University of Sydney, in collaboration with NSW DPI. It was part of a jointly funded project supported by the Rural Industries Research and Development Corporation’s Horse Research Program and the Animal Biosecurity Cooperative Research Centre for Emerging Infectious Diseases.