COLUMBUS, Ohio – Songbird deaths have been reported in at least 10 states and the District of Columbia, and officials are trying to determine what’s killing them.

Dead and sick songbirds had been found in Kentucky, Indiana and Ohio as of press time. Other states reporting dead and sick birds were Delaware, Florida, Maryland, New Jersey, Pennsylvania, Virginia and West Virginia.

Songbirds such as blue jays, American robins, common grackles, starlings, northern cardinals and brown-headed cowbirds have been affected, according to various state departments of natural resources. Symptoms include eye swelling, crusty discharge around the eyes, the inability to stand, ataxia (falling to the side) and other neurological signs.

Testing has ruled out avian influenza, West Nile Virus, Salmonella and several other viruses, the Indiana Department of Natural Resources (IDNR) said. Other diagnostic tests are ongoing, the agency added.

In Ohio, dead or sick songbirds had been found in about a dozen counties, said Laura Kearns, wildlife biologist with the Ohio DNR’s Division of Wildlife. Kearns said she first heard about the situation in the state in late May or early June.

“The most frustrating part is not knowing what is causing it,” she noted. “We want to do what’s in the best interest of the birds. Some people are frustrated by the recommendation to take down bird feeders. That’s the best thing we have right now. It’s frustrating not being able to say, ‘just do this.’ We’re just guessing right now.”

Departments of natural resources in several states have recommended removing bird feeders, including those for hummingbirds, until the situation is over. They’ve also suggested removing birdbaths. Feeders and baths should be cleaned with a 10 percent bleach solution and put away after allowed to air dry. Pets should be kept away from sick or dead birds. Disposable gloves are recommended when handling the birds.

“Asking people to remove bird feeders was more of a precaution,” Kearns explained. “If you don’t know (what it is), you assume it could be some kind of infectious disease. Keeping birds from congregating is one way to slow it down if it is transmissible.”

Birds will find other sources of food if feeders are removed, said Allisyn Gillet, IDNR state ornithologist.

“There are abundant food resources available to birds at this time of the year, including insects, berries, nectar and seeds,” she stated. “Birds will shift to those available food sources when feeding is stopped.”

The Ohio Department of Agriculture has reached out to the poultry industry in the state to increase awareness, biosecurity and preparedness for potential impacts, said Dr. Dennis Summers, the state veterinarian and interim chief of animal health.

“The state veterinarian’s office is aware of this issue in wild birds,” Summers said in an email. “At this time, there is no conclusive diagnosis being reported and we are communicating with ODNR on their testing efforts and findings. As these are wild birds, we have been communicating with concerned citizens and directing them to ODNR.”

The Indiana State Board of Animal Health (BOAH) has recommended that hobby flock owners take steps to protect their poultry. Without specific information on the cause of the deaths and sicknesses, the agency said, poultry owners are encouraged to protect their domestic flocks from potential exposure to wild birds.

“We always recommend good biosecurity for small flocks,” Dr. Bret D. Marsh, Indiana state veterinarian, said in a press release. “When something unknown and unforeseen like this happens is when keeping flocks secure really pays off.”

BOAH recommended keeping poultry in a fenced space and contained to the coop or barn at night. Chickens shouldn’t be fed outdoors where wild birds may also feed. Feed pans and waterers should be cleaned and sanitized.

The suggestions for hobby flock owners have been made out of an abundance of caution, said Denise Derrer, BOAH communications director. There have been no reports of any cases in poultry species, she noted.

As for commercial flock owners, “keeping wild birds out of contact with poultry is a normal course of business for those operations,” Derrer explained in an email. “Deterring wildlife is an important part of biosecurity. Birds in commercial flocks are not typically exposed to outdoor conditions like small, hobby flock birds are. So, at this point, we don’t have particular concerns about the mysterious issue with songbirds affecting our commercial poultry sector.”

In Indiana, more than 280 cases of dead or sick songbirds have been reported in more than 50 counties, Gillet said earlier this month. She said the number of reported cases is likely low and the actual number could be in the hundreds or near 1,000.

A July 2 update from the Kentucky Department of Fish and Wildlife Resources said the agency had received about 250 reports of dead or sick songbirds it believed are related to the unexplained illness.

Testing is being done at several locations, including the Indiana Animal Disease Diagnostic Laboratory and the U.S. Geological Survey’s National Wildlife Health Center, Gillet said.