ANNAPOLIS -- The Maryland House of Delegates bit back Monday in a feud between the General Assembly's two chambers over a bill to hold dog owners more responsible when their animals bite, killing a Senate provision that would have made it harder for owners to defend themselves in court.

The bill would require dog owners to prove their animals aren't dangerous if they are sued for a dog bite. The measure stems from a 2012 ruling by Maryland's highest court that said pit bulls were "vicious and inherently dangerous" dogs. Under the ruling, pit bull owners were automatically liable if the animals bit someone. Animal rights advocates argue that unfairly singles out pit bull owners while the burden of proof shifts from owners to victims if they are bitten by other breeds.

At issue is the standard of proof dog owners are held to if they are sued by victims. Lawmakers originally agreed to "a preponderance of the evidence" standard, in which an owner had to prove only that a majority of the evidence shows his dog isn't vicious.

However, the Senate passed a version of the bill requiring owners to prove with stricter "clear and convincing evidence" that their dogs aren't dangerous. The only higher standard is "beyond a reasonable doubt."

The House amended the Senate's bill to use the lighter burden of proof before passing it 133-0 on Monday. The bill is expected to go to a conference committee to work out a compromise.

Del. Luiz Simmons, D-Montgomery County, who ushered the bill through the House, isn't hopeful that the two chambers will be able to reach an agreement before the General Assembly session closes in a week.

"I'm not going to agree to something that's grossly unfair [to dog owners]," Simmons said. "If they want strict liability, they're not going to get it."

Simmons said trial lawyers prodded the Senate to adopt the stricter standard.

The Maryland Association for Justice -- which lobbies for trial lawyers -- did not respond to a request for comment Monday evening.

The bill's Senate sponsor -- Simmons' Montgomery County Democratic colleague Sen. Brian Frosh -- said he's more confident the conference committee will reach a compromise.

"The differences between the two bills are not that great," Frosh said. "I don't have any idea at this point [what the conference committee will do]. I just know that the differences aren't that big."