Agriculture and Food Minister Terry Redman said after two years of surveillance testing and monitoring, the properties had been reinstated in the bluetongue virus free zone by the National Arbovirus Monitoring Program for the purpose of international trade.

"BTV has been present in northern Australia for more than 20 years and is endemic in much of the Kimberley," Mr Redman said.

"It is a potentially serious disease of sheep, and can also infect cattle which act as a reservoir but rarely show symptoms."

Mr Redman said the virus was detected on two Pilbara cattle stations in 2007 and had resulted in a significant portion of the region being placed in a BTV zone.

"The Agriculture and Food Department has conducted surveillance testing on these and other Pilbara properties for the past two years to demonstrate BTV-freedom," he said.

"Some of the more lucrative international markets for live cattle such as Israel and Saudi Arabia require the cattle be sourced from BTV-free zones."

Mr Redman said the Israel market was worth on average about $29 million and the Saudi market $13m to WA, and were the second and third biggest live export markets for WA cattle after Indonesia.

"Most countries that take live cattle from WA, including several in the Middle East and those in South-East Asia, do not require animals to be sourced from a BTV-free zone," he said.

"However, the Israel and Saudi markets can be worth up to $60/head more in price, which is significant."

The department will continue to carry out surveillance in the Pilbara to meet national monitoring requirements.

The surveillance program is jointly funded by industry and the department.