An ailing elephant at the National Zoo is giving a local focus to a growing debate about whether zoos offer a suitable environment for elephants, particularly if the animals are often confined to small spaces.

Toni, one of four Asian elephants at the animal park, is receiving treatment for arthritis in her legs. The zoo said in September that if the condition worsens, she might have to be euthanized -- a possibility that has prompted two animal rights groups to push to have Toni moved to an elephant sanctuary, where she would have more room to exercise and be on softer ground.

Toni is kept at night in a room with rubberized flooring. She shares about 32,880 square feet of outdoor space with the three other elephants and has access to a pool and an exercise area.

"The zoo is giving Toni the best medical care it can, but it's only treating the symptoms, not the cause," said Amy Mayers, a Northwest Washington resident who has helped organize Friends of Toni. "Let's give her a second chance."

Mayers and seven others distributed leaflets yesterday outside the zoo's Connecticut Avenue NW entrance and asked passersby to sign a petition urging the zoo to move Toni to the Elephant Sanctuary in Hohenwald, Tenn. The local group is working with In Defense of Animals, an organization that opposes the institutionalized exploitation and abuse of animals.

National Zoo officials and other zoo managers say the animal rights groups have misrepresented Toni's situation and are ignoring the important conservation and research role zoos play in helping endangered Asian and African elephants.

"We're nowhere near that worst-case scenario" of euthanizing Toni, the zoo's new director, John Berry, said in an interview last week. "All the discussion and plans now are on her care and keeping her happy and healthy."

Tony Barthel, the zoo's assistant curator for elephants, said the elephant's arthritis medication, which includes 9,000 milligrams of ibuprofen twice a day, is helping ease the pain. She has lost weight, he said, probably muscle mass that he hopes to build up again by increasing her exercise.

"We're encouraged by how well she is getting around," Barthel said, adding, "This is an animal we love. Euthanasia would be the absolute last resort."

Toni, 39, came to the National Zoo in 1989 from Scranton, Pa., where she lived alone in a decrepit concrete enclosure and was afraid to step on dirt. She suffered an injury there to her left front leg, causing her to walk stiffly and stand awkwardly. The zoo's staff helped Toni learn to socialize with the other elephants, encouraged her to swim in the elephant yard pool and nursed her through kidney problems in 2001. Barthel said the leg injury caused Toni's arthritis.

Berry said a sanctuary is not the answer for Toni, who needs constant medical care. He does not want to separate her from the only elephants she has known, and he said experts have told him that Toni probably would not survive being trucked to Tennessee.

Elephants, who can live into their sixties, typically walk 30 miles a day in the wild in search of food. Captive elephants often develop foot problems and arthritis. There are about 150 Asian elephants and 150 African elephants in zoos in North America, though some zoos, particularly those in colder climates, have been reevaluating whether they should exhibit them because of insufficient exercise space in winter. The Detroit Zoo recently transferred its two elephants to a sanctuary in California.

Carol Buckley, who co-founded the Tennessee sanctuary in 1995, said she has seen dramatic improvements in arthritic elephants brought to the 2,700-acre complex. The sanctuary, she said, has the equipment to successfully move even ailing elephants long distances. Without the move, she and other advocates for animals said, Toni's condition will worsen and she will face a premature death.

Mike Keele, a deputy director at the zoo in Portland, Ore., who heads the elephant Species Survival Plan for the American Zoo and Aquarium Association, said zoos that exhibit elephants should keep them off of hard, unyielding surfaces; give them plenty of room to exercise, including swimming and mud wallowing; and, ideally, provide a range of life experiences, including mating.

Zoos, he said, are working to make sure that they provide this environment.

The National Zoo concedes that its elephant facility, built in the 1930s on less than an acre, needs to be improved. A plan for a 2.6-acre facility has been sent back to designers, Berry said, because he thinks it needs to be two to three times larger for the six to eight elephants the zoo hopes to exhibit.

"The elephant is the biggest animal in the zoo," he said. "It ought to have the biggest space."