By CBS3 Staff

WEST CHESTER, Pa. (CBS) — A multi-state investigation was all sparked by a rabid dog. The dog was one of a few dozen animals imported by an animal rescue organization from the Middle East to Chicago’s O’Hare Airport.

The animal eventually ended up with a Chester County family.

READ MORE: Thursday's Storms Break Record For Most Tornadoes In Tri-State Area In Single Day

Last week, the CDC issued a temporary suspension of dogs from high-risk countries, and while this is only the fourth import case recorded since 2015, both Pennsylvania and New Jersey are on alert.

“When I rescued her, it was through a foundation that was well known,” dog owner Nicole Antonini said.

Pet owners are on high alert after a dog imported to the U.S. and placed with a Chester County family tested positive for rabies.

“I go to the dog parks a lot, so it was kind of alarming to make sure that I don’t know everybody that’s there,” Antonini said.

The CDC confirms the dog was one of 34 animals flown to Chicago on June 10 from the Middle East, and from there distributed to animal rescue groups in five states, including Pennsylvania and New Jersey.

“The number one sign is usually a change in behavior,” said West Chester Veterinary Medical Center Dr. Rob Mowday.

While rabies is rare in the U.S. because of vaccines, it’s fatal if contracted.

READ MORE: Philadelphia Announces Phase 2 Of Street Cleaning Program Running Through November

“If your dog has rabies, then it could bite you and then you have to be concerned about rabies,” Mowday said.

Health officials are not releasing the names of the animal organizations or the at least 18 people potentially exposed, but say they have contacted anyone at risk.

“If we know an animal has contact with a proven rabid animal, we do give it rabies vaccine boosters,” Mowday said.

When in doubt, take your pet to the vet.

“It can take up to six months from the time they are infected before they show signs,” Mowday said.

The rabid dog has been euthanized. Which shelter the dog was at or rescue group has yet to be released.

Anyone with questions is urged to call their local vet or the Chester County Health Department.

MORE NEWS: Body Found In Northeast Philadelphia Positively Identified As Missing Woman Casey Johnston: Sources

CBS3’s Alicia Roberts reports.