Poultry farmers are being asked to exert extra vigilance after the Canadian Food Inspection Agency (CFIA) expanded its avian flu quarantine area.

Biosecurity measures are in full effect on the Woodstock-area turkey farm where the avian flu was found last week.

About 10,000 turkeys on the infected farm died of the disease and the remaining 35,000 were put down.

Initially, the CFIA put that farm and eight neighbouring farms under quarantine, but on Sunday that was expanded to a 10 kilometre radius from the initial outbreak - adding 20 additional farms to the quarantine list.

The CFIA says there have been no additional cases, but they are proceeding with caution.

Farmers are being urged to add extra precautions, including minimizing the opportunity for wild birds to come into contact with poultry.

“We’re all on high alert,” Kees Peeters, a Parkhill-area chicken farmer, said Monday. “It’s a big concern to us.”

The strain of the virus found  - H5N2 - has been found to be nearly identical to the one that triggered outbreaks in B.C. and nine U.S. states since late last year.

Japan, Taiwan, Hong Kong, Uruguay and Barbados have imposed trade sanctions as a result of the outbreak in Ontario.

With files from The Canadian Press