CHICAGO (CBS) – It’s a story we’ve been tracking for weeks — dogs getting shocked by manhole covers.

And it’s happening more often than most of us know.

Dog owners are reporting odd, scary and violent behavior from their pets, and manhole covers seem to be the common thread between incidents.

Yet, as Chris Tye reports, it’s a problem the City of Chicago doesn’t seem to want to tackle.

Kate Wall and her dog Annie have a regular dog walking route, a stretch of Addison near Lake Shore Drive.

There is one spot where Annie gets spooked.

“I kept thinking maybe it was her shadow,” she said.

Apparently not.

John Harding’s dog Mojo was on same block last Sunday, when Mojo bit his hand (which he never does) and was in wrenching pain for 40 minutes.

“Just went down shaking, and I was panicking,” Harding said. “I wasn’t sure if he was dying the sidewalk or what was happening.”

He thinks it was an electric current on a manhole cover.

At a location not two miles away on that same day, authorities cordoned off a manhole cover at Wellington and Halsted with bio-hazard tape.

Lina Schwartz’s dog Bowdie bit her hand in a nearly identical incident.

“This is not a one-off situation,” Schwartz said.

But it’s a situation the city doesn’t have answer for. CBS 2 called every day this week

A lack of clarity is leaving Annie’s mom feeling concerned “because I’ve never seen her behave that way.”

And Mojo’s dad convinced “that there’s electric current running through the public sidewalks. It’s frightening.”

Both of the dogs that bit their owners from these apparent “shocks” are doing well, but their owners tell us they aren’t quite back to their normal selves.