The roster of the deceased at Rosa Bonheur Memorial Park in Howard County reads like a who's who of Washington area pets: Mary Ann, a beloved elephant from the Baltimore Zoo. Willie II, a black Labrador retriever owned by Comptroller (and former governor) William Donald Schaefer. Tiny B.B., a canine mascot for the Washington Bullets.

But what was once notable as a pioneering pet cemetery -- the first in the nation to allow people and their pets to be buried side by side -- has devolved over the past decade into a dilapidated eyesore, plagued by allegations of theft and persistent speculation that the burial ground will soon be turned into a strip mall. The current owner won't comment on any plans.

At Bonheur, unkempt grass is knee-high. Rusty beer cans and a tire litter the grounds. A few weeks ago, a large oak tree fell onto the grave of Loki, a Prince George's County police dog, but no one has moved it.

"This is a sin before the Lord," said Joyce Williams, 65, who cried as she walked between sunken graves filled with water and trash to reach the place where Wee Lady Lexie, her 6-year-old Yorkshire terrier, is buried in a tiny pink coffin. "How can someone care more about dollar bills than respecting the dead?"

The decline of Rosa Bonheur Memorial Park highlights the precarious existence of pet cemeteries, which are unregulated in most states, and their increasing transformation into easy targets for developers in the Washington region and across the nation.

"The problem is that the property is worth just too darn much," said Robin L. Lauver, president of the National Association of Pet Funeral Directors. "Now you have hundreds of these of pet cemeteries that can be sold off as building lots. And there are no laws to stop it."

Virginia is one of the few states that has tight restrictions on pet cemeteries. Prompted by outrage in the 1990s over plans to build a shopping center atop Evergreen Pet Cemetery near Richmond, the General Assembly required owners of pet cemeteries to promise that they will use the land for no other purpose and put $12,000 into a perpetual care fund. Maryland and the District have no such laws.

Named after a 19th-century animal painter, Rosa Bonheur Memorial Park was founded in 1935 in Elkridge as one of the world's first pet cemeteries. Its decision in 1979 to allow owners to be buried next to their pets made national headlines.

The 22,000 animals buried there include obscure goldfish and parakeets as well as more famous animals like Wiggles (a 29-year-old champion horse) and Corp. Rex Ahlbin (a World War II combat dog who died during fighting at Guadalcanal).

At least 20 Homo sapiens are also buried there, according to former manager Marilyn L. Phillips. One of those, U.S. Army Pfc. Melvin D. Ward, killed himself by jumping out of an airplane without a parachute because he was despondent over the death of his 7-year-old dog, Moo, she said. They are buried next to each other.

But the celebrated cemetery fell into disrepair in the 1990s under the ownership of William A. Green. Grieving pet owners complained that Green would not deliver the funeral services for which they had paid hundreds of dollars.

Six days after Green gave a Baltimore couple the ashes of what were supposed to be their dogs Tessa and Suzy, police discovered their uncremated bodies in a cemetery shed, according to court documents.

Howard County and 16 pet owners brought criminal and civil charges against Green in 1996. He was convicted of misdemeanor theft and ordered to pay tens of thousands of dollars in restitution. Green could not be reached to comment.

Animal lovers rejoiced when Green declared personal bankruptcy and the pet cemetery was put up for auction. It was purchased by Gunter W. Tertel, a local businessman, and managed by Phillips, a cheerful animal lover.

But what the pet owners didn't know was that Tertel apparently never intended to continue operating the cemetery.

"He didn't want me to do any burials there at all," said Phillips, 68, who now lives in Alabama. "He just wanted to make sure his sheet-metal company next door could use the back of the cemetery for access to the road."

Phillips, who is a family friend of Tertel's, said that the cemetery continually lost money when she ran it and that Tertel had to use money from his other business to pay property taxes. She said she worked there for free and maintained the grounds almost single-handedly. "I think it's basically been closed since I left in 2002," she said.

"It may turn into a strip mall very soon," she added. "When I worked there, the land was valued at $2 million."

A woman who answered the door at the cemetery's former office said she had been hired to renovate the building for a new tenant, which she would not name.

The woman, who identified herself as Diane Hall, said she didn't know anything about a pet cemetery.

District resident Gail Zandel, 58, is afraid that the land will be developed and the animals' remains dumped in a communal grave. She is trying to organize a group of pet owners to buy the land and run the cemetery.

"It feels as if someone tried to dig up the human members of my family," said Zandel, whose three dogs, turtle and cat are buried at Bonheur. "This is my worst possible nightmare."

Some pet owners have given up. Mary Nelson, 60, of Pasadena said she couldn't stand to see the cemetery's condition during her weekly visits to the graves of Casey and Fancy, her black-and-tan boxers.

"All I would do is cry and cry, because it wasn't taken care of properly," she sobbed. "We put our money into this place thinking it's our pets' final resting place, and then we get this? It's disgusting. I wouldn't put an ant out there."

Five months ago, she had the dogs' remains exhumed and moved to a cemetery across the street. When her son, Ricky, died a few years ago, she had become so disillusioned with cemeteries that she had him cremated.

But Williams refuses to move her pets. She believes it would be sacrilegious. Instead, she pays someone to mow the grass around the graves of Lexie and her three cats -- Shiela, Midnight and Muffin -- and visits every few weeks.

"If necessary, I will chain myself to this tree to stop someone from digging up my animals," she said. "They were the loves of my life, and I will bust heaven and hell to make sure they rest in peace."

About 22,000 animals are buried at Rosa Bonheur Memorial Park in Elkridge.Joyce Williams had a dog and three cats interred at Bonheur and believes it would be sacrilegious to move them.