When Yvette Dobbie learned shelters in New Mexico were killing unwanted dogs and cats in gas chambers, she felt compelled to act.

Most shelters in New Mexico use lethal injection to euthanize pets, considered more humane than carbon monoxide poisoning, but four communities tenaciously held onto the tradition. She argued her case in Clovis, one of the largest shelters still using gas chambers, but met with fierce resistance. Some believed gas chambers were just as humane, others felt lethal injections would be more expensive, and most doubted the state would help with the transition.

"They were really opposed to the change," she said, "and I was an outsider."

So the Santa Fe resident assembled a team — Caroline Buerkle and Natasha Ning — and turned to the Legislature, believing it would take time to change the law. But the measure, which had the support of the governor and House Speaker Ben Luján, sailed through the both chambers, garnering only three dissenting votes in the House.

On Monday, Dobbie's hard work paid off — Gov. Bill Richardson signed the legislation into law, along with a bill that will make it easier for shelters to use lethal injection. Richardson also got the Legislature to allocate $100,000 to help shelters in Clovis, Jal, Lovington and Tucumcari make the change with such things as training.

"You made this happen," Richardson said to Dobbie after the bill-signing ceremony at the Santa Fe Animal Shelter & Humane Society. "One person can make a difference."

The new laws, which take effect June 19, will make New Mexico the 18th state in the nation to ban the use of gas chambers for euthanizing animals.

"We will be at the forefront. In other words, we're not at 48," Richardson laughed, adding that protecting animals has been a priority for his office. "We've worked hard to raise the standards and awareness in New Mexico."

Aside from banning cockfighting in the state, Richardson said his office and the Legislature has worked to increase spay-and-neutering efforts, improve and fund animal shelters and improve animal-control practices. Some animal-welfare issues, such as the ban against gas chambers, are difficult issues to sell in such places as Clovis.

"There is a more humane way to euthanize pets," Richardson said, "and we have to enforce it."

The American Humane Association considers lethal injection the only acceptable method of euthanasia for cats and dogs in animal shelters.

Clovis Mayor Gayla Brumfield, who joined the governor in the signing, said concern about cost, confusion and a we'll-do-it-our-own-way" mentality led to strong opposition to lethal injection in her southeast community. But the discussion led to an animal task force that has sparked interest in a spay-and-neutering program and a licensing program.

Brumfeld said she hopes her community can now be a leader.

"We're going to work together with the state to make this happen," she said. "I truly believe that a society that treats their animals humanely is a society that will survive."

Luján, D-Nambé, said it was never the lawmakers' intent to force shelters out of business by burdening them financially with new requirements: "It was just a way to address a way of being more humane to our small animals."

That sentiment was echoed by House Majority Leader Ken Martinez, D-Grants, who sponsored the legislation. Martinez said people often think of legislators who create change, but it always starts with advocates who believe in an issue.

"It wasn't us wanting to get into the communities and force the issue," he said. "It was everyone coming together and finding a solution."

The second bill signed by Richardson allows technicians to administer lethal injection to cats and dogs instead of veterinarians. That will ease the financial burden on the shelters.

It's not easy to euthanize pets, said Mary Martin, the Santa Fe shelter's executive director, and some shelters are resistant to change. But it's important to do it humanely.

"We need to own the fact that these animals in our possession are our responsibility," she said. "You can't just put them in a box and kill them. It takes a courage; it takes a courageous staff, to care for the animals, to nurture them and then to have to put them down. That's amazing."

Alix Novack, a Santa Fe woman who spearheaded a rescue effort that has saved more than 150 dogs and cats from the Clovis shelter, said she'll now work on setting up a transfer program for that area's unwanted dogs and cats — similar to a program in Española, which sends some animals out of state for adoption.

"It's a wonderful day for everybody," she said about the bill signing, "but especially for the animals."

Dobbie, who, along with her husband, Steve, support and donate to several animal causes, said the legislation brought together a large coalition of animal groups. "There are a lot of wonderful animal people here in New Mexico," she said.

She plans to continue being an advocate for animals. In December, Dobbie was appointed by the governor to the state's Animal Sheltering Services Board. "I hope to be a positive voice on the board," she said.