By Dr. Scott Ford
A highly-pathogenic avian influenza (HPAI) strain was isolated from chickens in the UK last November. This strain rather quickly escaped efforts to contain it and passed on to the Middle East in late December, where it resulted in the deaths of over 5,000 cranes in Israel and the culling of half a million production poultry. Not long later, it made landfall in the US and has gradually spread to about half the country. Our first case occurred in Wisconsin in a production poultry flock in Jefferson County in mid-March and resulted in the culling of 2.7 million chickens and has since hit a handful of backyard flocks and production farms since.
HPAI has also affected wildlife and a recent case of a bald eagle that developed neurologic symptoms caught the public’s attention recently. The stricken eagle was found in Bay View, a suburb of Milwaukee, and the Wisconsin Department of Natural Resources responded and retrieved it. Because of the potential for HPAI to infect other birds in wildlife facilities or at least disrupt activities due to quarantines, wildlife centers are limiting the intake of wild birds, especially those that exhibit neurologic symptoms such as stumbling, convulsions, or incoordination. The eagle had such symptoms and was euthanized the next day. Test results for avian influenza are still pending. It’s worth noting that eagles often suffer neurologic impairment as a result of collisions or lead intoxication. I have not been in direct contact with Wisconsin Humane Society, which is where the eagle was taken, but I’m assuming that they performed an in-house lead screening and radiographs to check for lead in the GI tract or signs of trauma. They probably also performed an ophthalmologic exam to check for secondary signs of head trauma.
I was contacted by two different news stations and interviewed regarding eagles and avian influenza (see links above). The pieces are great but you may have additional questions. First of all, I’d like to remind everyone not to panic. The strain that is circulating is not likely to infect people under normal circumstances. However, if an affected bird bit or scratched you, the potential is increased so keep your distance from any dead birds or those exhibiting unusual behavior. Per the DNR’s website, you can contact the DNR Wildlife Hotline by emailing DNRWildlifeSwitchboard@wi.gov or by leaving a voicemail message for a return phone call at 608-267-0866.
Avian influenza is extremely common in the environment and circulates all over the world via migratory birds, especially waterfowl, gulls, and other sea and shore birds. Most strains are of low pathogenicity and may not cause any noticeable symptoms. But when a highly pathogenic strain spreads, it becomes a serious danger to endangered populations of wild birds and to our own food chain. Do your part to limit the spread by keeping your chickens contained until the current epornitic (a fancy word for a bird epidemic) is over. If you feed wild birds, consider stopping for a while, particularly if you have pet chickens, ducks, or other birds of your own. My own chickens are not happy about being contained in their pen, despite the fact that it’s pretty spacious, but hopefully they’ll be out soon and enjoying the summer.
I’m including some resources below you may want to check out. I’d also love it if you post comments or questions below and I’ll do my best to answer. Stay safe!