To declaw a cat, you amputate each toe at the first knuckle, taking off bone along with tendons and the claw. This is a controversial operation, and some veterinarians say it can lead to lifelong complications, pain, and lameness.

Declawing is illegal in most European countries and in Britain, where it is considered cruel. In Israel, declawing a cat could land you a yearlong prison sentence and a fine of around $20,000.

“The rest of the world recognizes it as mutilation,” said Jennifer Conrad, a veterinarian who runs The Paw Project, an anti-declawing group.

But the procedure is still relatively common in the U.S., where surveys suggest about a quarter of people’s cats are declawed. According to a 2011 AP poll, 55 percent of cat owners approve of the surgery, though declawing opponents say most people don’t fully understand what it entails.

There are a couple of ways to declaw a cat. Many veterinarians use shears to lop off the toes. A scalpel works too. More recently, some places do the job with lasers.

In recent years, Conrad’s group has led successful efforts to ban declawing in several cities in her home state, including Los Angeles, San Francisco, and West Hollywood.

Now, it has its hopes pinned on New York, which could become the first state in the nation to outlaw the procedure.

New York state assembly member Linda Rosenthal (D) is the author of Assembly Bill 1297, which would make it crime for anyone to declaw a cat or other kind of animal. The measure recently gained Republican co-sponsors in the senate, increasing its chances of advancing, though it is still at the committee stage. (A similar measure stalled in committee in Hawaii earlier this year.)

Rosenthal, who represents the Upper West Side in Manhattan, is a prolific sponsor of animal-protection laws. Last year, she pushed through a bill banning the tattooing or piercing of pets. “People often use their animals in very selfish ways,” she said—including declawing them.

Her ban would allow declawing for medical reasons—if, say, the cat’s toes become infected and have to be amputated. But such situations are rare. Owners declaw their cats because cats scratch.

“This is mostly done because people care more about their furniture than about their cats,” Rosenthal said.

The Humane Society of the United States and the American Society for the Prevention of Cruelty to Animals both strongly discourage declawing. Scratching is natural behavior for cats, they say, but cats can be trained to use scratching posts instead of honing their claws on the sofa. Their nails can be trimmed, or covered with soft plastic caps.

Last July, the American Veterinary Medical Association changed its stance on declawing, calling it “major surgery that should only be performed after alternatives have been sought to prevent destructive clawing.” The group now characterizes the procedure an “amputation.”

But some veterinarians argue that declawing should be still allowed as a last resort. People with weak immune systems could be infected from cat scratch wounds. Scratches are also threatening to those who bleed easily, like hemophiliacs or people on blood thinners.

The (human) medical establishment is skeptical of declawing. In their guidelines for HIV patients, the Centers of Disease Control and the National Institutes of Health say that declawing cats is “not advised.” Instead, they warn HIV positive people to be careful around cats and avoid “rough play.”

Declawing opponents add that cats who lose their claws—a primary defense mechanism for them—may resort to biting, which is more dangerous.

Some veterinarians also make the case that declawing helps keep cats in their homes. If people are not allowed to declaw a cat that’s causing problems, they might send it to a shelter. Given the choice between declawing a cat and euthanizing it, isn’t the amputation more humane?

Conrad, the anti-declawing activist, says that’s a false dichotomy, and that declawing a cat won’t necessarily solve its behavioral problems. Pain from the surgery might cause a cat to abandon its litterbox; might cause it to become less friendly and bite more.

There isn’t solid evidence, one way or the other, about what declawing does to a house cat long-term. Most of the studies rely on self-reported data from pet owners. And unlike dogs, cats instinctively conceal signs of pain, making it hard for owners to notice unless they are paying close attention.

The lack of evidence cuts both ways. It’s unclear how much cats suffer from being declawed. It’s also unclear whether it’s an effective way to stop a cat from acting out.

“There is no good scientific literature proving that declawing is a good thing to do,” Conrad said. “The burden of proof should be on people who want to declaw.”

Conrad, who has produced a documentary about declawing, met with Rosenthal last year to talk about legislation. The New York bill is similar to the bans that Conrad helped pass in several California cities.

Like those laws, the New York bill also has a loophole. It would outlaw declawing surgery in the state, but it would not stop people from bringing their cats to neighboring states for the operation. Rosenthal says the law would still serve as a deterrent; it would educate cat owners and would halt what she says is a culture of routine declawing.

“This is frankly a moneymaker for some vets,” she said “They do a spay, a neuter, and it’s like ‘supersize me’—let’s throw in a declaw.”

Rosenthal believes that many cats would be saved from the operation if owners understood that declawing involves amputating part of the toe. She’s a cat owner herself.

When her 17-year-old cat Olivia died a few years ago, Rosenthal swore never to get another one. “It was too painful,” she said.

But after a few months, she found herself back at the animal shelter. She left that day with two cats, both with claws intact. One of them she named Vida, after Vidal Sassoon, the hair stylist.

“She likes to comb my hair—with her claws,” she said proudly.