People are being asked to take down their birdfeeders while researchers try to determine the illness and its cause.

COLUMBUS, Ohio / SAEGERTOWN, Pa. (AP/KDKA) — Poultry farmers in Ohio are being warned by the state Department of Agriculture to implement strict biosecurity measures to protect wild birds dying from a mysterious illness.

Ohio officials are concerned the illness could potentially spread to chickens.

READ MORE: Allegheny County Health Director Says Delta Variant Is Fueling Rising Cases, Hospitalizations

“Biosecurity refers to everything that owners do to keep diseases away from their flocks. It is an active effort that owners can practice every day,” said Dennis Summers, interim State Veterinarian for Ohio in a statement from the department.

Several other counties across the state are facing the same outbreak, the Ohio Department of Natural Resources reported. The disease has been detected in birds in seven other states, including Pennsylvania.

The Tamarack Wildlife Center in Saegertown, Pennsylvania reported that a fledgling American Robin from Erie County was taken to their facilities for treatment with apparent symptoms of the illness but did not survive.

The disease makes birds’ eyes swell and emit a crusty discharge. It can also cause neurological damage and become fatal.

Researchers have not identified any definitive illness yet. Last month, Ohio residents were asked to take down bird feeders and bird baths to stop the spread of the illness, and residents in Pennsylvania are being asked to do the same by some officials.

READ MORE: 'Itchy Mites:' Preventing Bites And The Itch That Comes With A Mite Bite

People are advised to clean their birdfeeders with a 1:10 bleach solution but to not put them back out, according to the Tamarack Wildlife Center.

Poultry farmers have been recommended to limit visitors and ensure workers wash their hands before and after touching live chickens. They also must use disposable boot covers or regularly disinfect their boots.

The state agriculture agency suggests that farmers should closely watch for dead or dying wild birds on their property. It is suggested that chickens be kept in a fenced pen.

“It is critical that flock owners look for signs of illness and report any unusual illnesses in your birds,” Summers said.

If you live in Pennsylvania and find a dead bird or multiple dead birds with these symptoms, you can report it here. If the bird is alive, you can locate a nearby rehabilitation center that will pick it up here.

MORE NEWS: Pittsburgh Weather: Temperatures Continue Rising On Thursday

(TM and © Copyright 2021 CBS Broadcasting Inc. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)