December 20, 2011, 7:05 pm
By NINA BERNSTEIN

Ruth Fremson/The New York Times

Nurses protesting on Tuesday outside the headquarters of Cerberus Capital Management, which operates several hospitals, used inflatable dogs instead of the familiar inflatable rats.

Instead of the inflatable rat that has become ho-hum at union protests in New York, a giant three-headed dog with fangs was the effigy on display as about 250 unionized nurses rallied outside the Midtown headquarters of the private equity firm Cerberus Capital Management.

Last year the firm added 10 mostly Catholic community hospitals in the Boston area to its portfolio, promising to keep the same level of services or to provide even better services. But carrying signs that proclaimed “Cerberus Is a Lying Dog,” and that urged “Get Wall Street Out of Health Care,” members of the nurses’ union, National Nurses United, accused the firm of proving to be more like its namesake, the canine monster in Greek mythology that guarded the gates of hell.

“The Cerberus company has created a hell of its own,” said Karen Higgins, a co-president of the national union, echoing charges by its Massachusetts affiliate that Steward, the health care company created by Cerberus, has cut patient care to increase its profits.

Among the speakers outside Cerberus’s headquarters at 49th Street and Park Avenue were two nurses who told of corporate consultants cutting the amount of juice and bread available for patients at night at two Cerberus-operated hospitals.

Another nurse said that after she organized a union at a third hospital, a minor medication error was used as the pretext to fire her.

Christopher Murphy, a spokesman for Steward, called the allegations “totally fabricated” as part of a dispute over pensions, which is now in arbitration. The union’s campaign “has nothing to do with improving health care or even the conditions of their own nurses,” who are highly paid and working at award-winning hospitals, he said. “It is an attempt to pressure our hospitals to provide richer benefits.”

Cerberus, which manages about $20 billion in capital and owns companies with revenue of about $40 billion, is known for its ill-fated purchase of Chrysler before the government stepped in, and its more recent acquisition of major gun manufacturers. The nurses took advantage of its name to sing carols with a twist to bemused passersby, like “Dogs of hell, Dogs of hell,” to the tune of Jingle Bells, and “Who Let the Dogs Out.”