Avian influenza or “bird flu” is hitting Bay Area poultry farms hard, with a quarter of a million birds euthanized in Sonoma County this week alone. Mike Weber, the co-owner of Sunrise Farms in Petaluma, says around 82,000 of his egg-laying chickens had to be euthanized after birds started testing positive for avian flu.

The Food Authority noted that it might be possible that foxes are more susceptible to avian flu infections than mink. However, the agency also suggested that infection prevention protocols may not have worked as well at fox farms compared to facilities that raise mink. The authority has now confirmed avian influenza cases at a total of 42 fur farms in Finland.

The Centers for Disease Control and Prevention reports more than 53 million birds across the U.S. have died from highly pathogenic avian influenza. The CDC’s count of 4,000-plus infected is far from reliable. The disease contracting to people is believed to be extremely rare.

The Yukon is the latest place to be hit with avian flu cases as an outbreak continues to spread across the country. Officials from the department of environment said in a press release Friday that two waterfowl carcasses in southern Yukon tested positive for the H5N1 virus strand. The Yukon government is asking residents to report sightings of sick or dead birds to their TIPP line at 1-800-661-0525.