A few years back, a lawyer sued President Bush in Hawaii on behalf of all the world’s whales, porpoises, and dolphins. Although the case was dismissed, the outcome gave animal rights lawyers a glimmer of hope. At the time, the 9th U.S. Circuit Court of Appeals decided that it saw “no reason” why the Constitution prevents federal courts from hearing cases brought in the name of animals. All that was needed, the 9th Circuit suggested, was an act of Congress.

Congress hasn’t been forthcoming with such a law.

Still, there are animal rights lawyers who haven’t given up the search for their holy grail: a court decision allowing lawyers to bring suits directly on behalf of one or more animals. Some lawyers who specialize in humans, however, are doubtful that the law will ever evolve to the point where lawyers could go to court on behalf of thoroughbreds they claim don’t want to race in the Kentucky Derby or outdoor dogs who perhaps want to become indoor dogs.

Meanwhile, animal rights lawyers are racking up other victories, often by filing suits in the names of people who claim to have an emotional or other interest in the treatment of animals that don’t belong to them.

The Humane Society currently has a temporary court order preventing the killing of sea lions accused of depleting the salmon stock along the border between Oregon and Washington. The lawsuit was filed not in the name of the animals but on behalf of hikers and others who say they research and have grown to appreciate the sea lions.

A large amount of animal litigation involves pets. Just two years ago, a judge in Queens issued a protection order forbidding a man to come near a particular bichon frise.

There are instances in which courts have appointed lawyers to represent the interests of animals in suits where their owners are sued by the government.

A San Francisco-based attorney, Bruce Wagman, said that in 1999 a California court agreed that he could represent the interests of an adult chimpanzee named Moe in a dispute between Moe’s owners and the city of West Covina in California. The case settled, with Moe going to an animal sanctuary, before Mr. Wagman got to press the chimp’s case in court.

Moe made the news years later when one of his former owners was hideously mauled by two other chimps while visiting the sanctuary.

Just this year in Virginia, a federal court appointed a law professor at Valparaiso University to advise it on what to do with some of the pit bulls seized from a former quarterback for the Atlanta Falcons, Michael Vick, who is in prison for running a dog-fighting operation.

In the last few decades, animal rights lawyers say, courts around the country have been more willing to take into consideration the emotional relationship between people and their pets. The Vermont Supreme Court is set to decide soon whether a couple, Robert and Susan Goodby, can sue for damages related to the loss of companionship over the death of two cats, which died after taking drugs prescribed by a vet.

It’s not just cat people who are bringing such suits. In a small county in rural Oregon, a jury awarded $135,000 to a family whose neighbor had poisoned its four pet dogs, the lawyer who won the case, Scott Beckstead, said.

“It’s the largest verdict awarded for the intentional killing of companion animals,” Mr. Beckstead, said. “These were old mixed breed dogs that didn’t have any particular market value.”

Suits such as these were not always allowed, legal experts say.

“Traditionally you could only recover the market value of an animal,” an attorney with an animal law practice in Chicago, Amy Breyer, said. That once limited lawsuits over animals to livestock, she said.

Still, Steven Wise, who has taught the field at several law schools, including Harvard, says animal lawyers can be more aptly said to practice “animal-slave law” than “animal-rights law.”

Mr. Wise, who is bringing the cat owners’ case before the Vermont Supreme Court, said he is in the midst of preparing another case, still five years away by his guess, that will ask a court to grant an animal “higher legal status — personhood if possible.”

In the search for the ideal plaintiff, Mr. Wise is considering the chimpanzee, dolphin, gorilla, orangutang, or perhaps the African Gray parrot, animals he described as “cognitively complex” and “similar to us.”

An ape, depending on its situation, might possess any number of possible legal claims. Mr. Wise said a case could involve an animal held in a research facility or one that appears in movies.

When the cateceans sought their day in court against the president in a case over the Navy’s use of SONAR, none of the plaintiffs — no surprise — were present for the court hearings. The day may not be far off, animal lawyers say, when animals are not only present in the courtroom, but even participating in the proceedings.

Someday, Mr. Beckstead said, “a chimpanzee could express himself through sign language to a judge to the point where the judge feels that the chimpanzee was able to articulate its own interests.”

“That would help make the case for recognition of legal personhood,” he said.

That day has clearly not arrived. At least not in Texas, where an appellate court threw out in January a breach of contract suit filed on behalf of several chimps, some dead.

“A lot of people talk about it, a lot of people write about it, but it hasn’t succeeded,” the vice president of litigation at the Humane Society, Jonathan Lovvorn, said of getting courts to grant standing to animals.