There are more dogs than kids in the City by the Bay. So it stands to reason dog owners carry a lot of clout _ so much so they believe their endorsement can sway the upcoming mayoral race.

Dog lovers have formed a political action committee to promote the interests of their four-footed friends, namely space to run free in one of the world's largest urban national parks. And they are calling on mayoral candidates to defend their stands on canine affairs.

"We expect the dog vote to be a game-changer," said Bruce Wolfe, president of DogPAC, which held a forum attended by several mayoral hopefuls Saturday.

There are an estimated 150,000 dogs in the city, compared with some 108,000 children, according to the San Francisco Society for the Prevention of Cruelty to Animals and the 2010 U.S. Census. More than 800,000 people are sandwiched into 7-by-7 square miles in the city named for St. Francis, patron saint of animals.

As more parents seeking new schools and lower housing costs move out of the city, more straight and gay couples, as well as aging baby boomers, are choosing canines over kids. San Francisco is renowned for its dog parks and, like Paris, many of its restaurants and shops welcome pampered pooches in their leopard-print sweaters and bling-ringed dog collars.

City officials typically can be found at animal fairs and forums. Debates over the funding of the city's Animal Control department and bans on the sale of shark fins and pet-store hamsters can turn into big brouhahas.

"Our four-legged family members and companions are some of the most important partners in life," said Wolfe, who has a disability and recently lost Charlie, his service dog of 10 years. "San Franciscans take their dogs very seriously."

Seven of the 16 candidates vying for City Hall's top job in the Nov. 8 election attended Saturday's DogPAC forum, where candidates were asked about the cost of dog licenses, trash cans in parks where owners can dispose of dog waste and pet-friendly rental housing for people who want to adopt foster animals.

Candidate Joanna Rees _ a venture capitalist with two dogs, Jack and Jill _ held her own "Bark in the Park" forum several weeks ago.

"Dogs are an important part of many families and neighborhoods across our community," said Rees. "Open lines of communication between City Hall and pet owners _ as with merchants, educators, parents, working families and other stakeholder groups _ are the foundation of good policy."

Some campaign websites even note where candidates stand on puppy policy.

"Making San Francisco a family friendly city means recognizing the multitude of ways in which we define families," City Attorney Dennis Herrera says on his site. "And in the city of St. Francis, that includes dogs and companion animals."

Herrera made national headlines in 2002 when he sued Petco Animal Supplies Inc. for the alleged mistreatment of animals after lengthy city investigations. The pet supply chain settled the lawsuit, and the rock star Pink sent her thanks in a photo pasted on his website.

Candidate John Avalos, a city supervisor, took the chance to take a swipe at his chief competitor, incumbent Mayor Ed Lee, who was not attending the forum and has been criticized for skirting some public events where he's thrown impromptu questions.

"As a mayoral candidate, I would ask the current mayor whether his Rose Garden strategy of avoiding debates and forums is keeping him from engaging with a group of real, engaged, and powerful San Francisco voters," Avalos said.

The big issue that has the city's dog owners on edge is an investigation by the National Parks Service as to whether it should close down great swaths of parkland in Marin, San Francisco and San Mateo counties where dogs are allowed to run off leash. The Golden Gate National Recreation Area, some 75,400 acres of open land and water, is nearly two and a half times the size of the city of San Francisco itself. The Park Service's proposed dog plan, which will be finalized next year, has elicited about 4,700 public comments on its website.

The Park Service is considering mandating leashes in some open spaces and fencing off some popular dog-walking areas. They and environmentalists want to protect some 1,200 native plant and animal species, including the Snowy Plover, a federally endangered shorebird.

The Golden Gate Audubon Society is working with the Park Service to find the right balance. Measures they're recommending would mandate that dog walkers be limited to three dogs each and that professional dog walkers be required to carry permits.

"It's hard to show people what's not there," said Mark Welther, executive director of the society. "But our people have been doing bird surveys in the Bay Area for 75 years, and time after time our bird-counters will tell us that in the areas opened up to dogs _ the birds have disappeared."

Fort Funston, a former military outpost of sand dunes and eucalyptus groves on cliffs that overlook the Pacific Ocean, is one of the most beloved dog parks in America. Dogs run free in joyous packs through trails that line the 35 acres of wilderness.

Wolfe and Sally Stephens, president of the dog owners' association, SF Dog, walked the Fort Funston trails last week and handed out leaflets to the dog walkers, urging them to attend the forum and help them decide which mayoral candidate they should endorse.

"It is miles and miles of smiles out here," Stephens said, as dog walkers cheered on Fritz, a plucky Dachshund who needs wheels on his hind legs to get around and keep up with his pack. "It's such a great community out here _ and people who don't have dogs just don't get that."