Allison Sheedy holds her Rhode Island Red hen, one of four female chickens she and her husband Dan McInnis keep for eggs in their backyard garden in the Chevy Chase neighborhood of Washington. (J. Lawler Duggan/For The Washington Post)

D.C. Mayor Muriel E. Bowser (D) is seeking to put an end to her city’s tolerance of an agrarian hobby that has taken hold in cities across the country: raising chickens.

In a raft of legislative changes attached to her pending budget proposal, Bowser proposes alterations to the District’s animal-control laws that would definitively ban the practice of keeping backyard chickens in the nation’s capital.

The move comes after city officials suffered a defeat last year at the hands of a pair of chicken-raising antitrust attorneys who live in Chevy Chase and who sued the District when the Department of Health warned them to remove the birds.

The litigation — which centered on ambiguities in D.C.’s Animal Control Act concerning the legal status of chickens — ended with the city beating a retreat and issuing Allison Sheedy and Dan McInnis a permit to keep their four backyard birds.

But Bowser’s proposed legislation would eliminate any wiggle room in the law for urban chicken-keeping, explicitly stating that chickens are not a “common cage bird” of the kind exempted by the regulations and giving the mayor power to “regulate the keeping of dogs, fowls, and other animals . . . to protect the public health, safety, and welfare.”

Department of Health spokeswoman Jasmine Gossett said the changes are meant to remove all doubt about what city officials continue to maintain is an existing ban on the raising of chickens. “The intent of the changes is to clarify that chickens and hens have been prohibited for the past 30 years,” Gossett said.

But McInnis said the proposed alterations are a clear admission that chickens are allowed under the legislative status quo. “It’s a mockable position,” he said. “They wouldn’t have to change the law if they were right.”

Gossett was unable to answer questions about what would become of the District’s existing chickens should an unequivocal ban go into effect.

McInnis and Sheedy aren’t waiting to find out. They have set up a website that warns of “backyard chickens in peril” and say they plan a full-on effort to persuade D.C. Council members to reject the proposed changes to the law. At the least, they said, the council should hold hearings on the chicken changes as an independent piece of legislation rather than rolling the issue into budget deliberations.

A petition put up on the site Wednesday night had garnered support from 80 people by Thursday afternoon, they said.

“Whether it’s your thing or not, it’s sort of a cool, interesting, quirky thing to do,” McInnis said. “It’s different. I think generally we should support people who want to do different, fun, safe things, and the city government shouldn’t be trying to underhandedly change the law to inhibit pet ownership.”

Once a sign of urban squalor, chickens have reemerged in recent years as newly chic denizens of the back yards of American cities. New York, San Francisco and Portland, Ore. permit residents to keep some number of the birds.

Residents in Arlington, Va. and Montgomery County, Md. have also fought in recent years for zoning changes that would allow them to keep chickens. The Rockville City Council in Maryland voted in 2015 to allow residents up to five hens.

The precise rationale for the District’s animus against chicken ownership is unclear. Gossett said she could not speak to the reasons for a chicken ban.

Asked about the law at an unrelated news conference Thursday, Bowser answered cryptically. “The provision is that we keep neighborhoods safe, and clean and rodent-free,” she said. (D.C.’s animal-control laws actually explicitly condone pet rodents.) “This is a city. And it’s not usually the chickens that are the problem but what they leave behind.”

Live poultry have been linked to salmonella infections. Last year the Centers for Disease Control and Prevention traced eight salmonella outbreaks across the country to backyard fowl, resulting in more than 200 hospitalizations and at least one death.

Aaron C. Davis contributed to this report.