Two animal welfare groups and the D.C. Department of Health have joined forces to capture and sterilize feral cats once a month with the aim of humanely reducing and eventually eliminating the city's stray cat population.

Several people went out in rainy weather Thursday to trap 16 scruffy animals, which were taken to the Washington Animal Rescue League's clinic in Northwest. Yesterday, the felines were neutered or spayed and treated for minor medical problems. The cats are to be returned to their colonies today.

Similar "Trap-Neuter-Return" forays in targeted neighborhoods will be conducted one day a month. The program, known as the District of Columbia Cat Assistance Team, is being operated by the rescue league and Alley Cats Allies.

Donna Wilcox, executive director of Alley Cat Allies, estimated that "thousands, maybe tens of thousands" of feral cats live in the District. These stray animals, some of them abandoned pets, often live in groups and forage for food from homeowners, restaurants or businesses. It is a tough existence that exposes the cats to disease and early death, and also creates a potential health hazard because some carry rabies.

"They have a very hard life," said Gary Weitzman, the rescue league's medical director. "It just breaks your heart."

The semi-wild cats are not considered adoptable, except as young kittens, because it could take years to tame them and shelters already are full of domesticated animals, Wilcox said. Some veterinary clinics in the District and Virginia neuter and spay hundreds of these stray cats a month, but no one has been tracking or keeping statistics on them until now, she said.

Yesterday, at the rescue league's Oglethorpe Street NW clinic, the captured animals garnered all the attention of a small staff of veterinarians and assistants. Male and female felines were housed in separate rooms before being brought in for surgery, usually two at a time. The mixed-breed cats were all colors and sizes, from scrawny, matted orange and white youngsters to a large, old gray tomcat with a head wound. Some came from the Petworth neighborhood, and others from an area near North Capitol Street and Rhode Island Avenue NW.

Before the cats were even examined, they were anesthetized.

"These are wild animals," Weitzman said. "We don't want to touch them until they can't touch us back."

Neutering the 10 males took about five minutes each. Spaying the six females required 15 to 20 minutes. After each procedure, the cat's left ear was notched, a universal sign indicating sterilization. The cats were given rabies and distemper shots, as well as post-surgical pain medication. They also were treated for parasites, ear mites and fleas and got a thorough grooming that included removal of matted fur.

The cats often have respiratory or bladder infections, eye problems and wounds from fights, Weitzman said, and are given antibiotics. If they are dehydrated, they receive fluids.

But cats with severe medical problems will be euthanized. Any captured kittens are kept for adoption, but any unborn kittens will be aborted. The 16 cats treated yesterday were found to be in reasonably good condition.

Scotlund Haisley, a former D.C. animal control officer who is the Animal Rescue League's executive director, said the clinic was closed yesterday so the staff could tend to the feral cats.

"We've created what we believe is an innovative program that will specifically target the feral cats in the District," Haisley said. "For these cats, the only alternative is euthanasia by animal control."

In May, the league began the region's first free year-round spay and neuter clinic for cats, dogs and other pets. Any pet owner, regardless of income, can request services.

The key to the success of the feral cat program will be the continued tracking of outdoor cat populations, Wilcox said. Her group is coordinating the efforts of trained volunteers who will work with the Health Department and area residents to assess each cat colony and provide regular monitoring.

The volunteers fill out forms for each monitored colony, taking note of the its location, size and any sterilization procedures and other veterinary care. Wilcox said her group is seeking more volunteers to trap and transport cats, and to foster captured kittens.

At the Animal Rescue League, Evelyn Wingfield carries an anaesthetized stray cat to the recovery room after veterinarian Solomon Perl finishes spaying it.