The Bureau of Land Management issued new rules this week for further protection of wild horses and burros that roam millions of acres of Bureau controlled land in the West.

The rules also are designed to prevent abuse of animals in private ownership under the bureau's adopt-a-horse program. Under that program, more than 15,000 mustangs and burros have been transferred to private owners in 47 states.

For years, the wild animals were preyed upon by hunters who sold carcasses for pet food. But in some areas of Nevada and California, the herds became so large, they caused overgrazing of valuable rangeland.

After animal protection groups raised an outcry, Congress passed legislation in 1971 to protect the horses and burros from indiscriminate slaughter. Amendments to the law in 1978 permitted private owners of horses and burros to obtain title to the animals, and set conditions on transplanting or destroying animals in overpopulated areas.

The regulations implement provisions of the 1978 amendments to the protection law.

Even with the 1971 law, humane organizations accused the bureau in a federal court suit in Nevada with failure to protect adequately wild horses and burros. They contended that large numbers of "adopted' horses were still being sold for pet food or put into a form of animal slavery -- as bucking horses on the rodeo circuit.

The lawsuit brought by the American Horse Protection Association and the U.S. Humane Society is awaiting a decision.

Russell Gasper of Washington, a lawyer for the association, had not seen the bureau's new rules and declined comment on whether they might satisfy the group. But he said he doubted the association would drop its lawsuit, because it wants a court ruling that the bureau must prepare an environmental impact statement before culling wild horse and burro herds.

The 1978 law and the rules just issued allow prospective owners to adopt up to four animals a year. To get title to the animals, the new owners must provide one year of humane care and provide a statement from a veterinarian saying the animal has been well cared for.

From then on, the new owner must provide humane care or face a fine up to $2,000 a year in prison, or both. The rules ban use of adopted animals for "commercial exploitation," including use as rodeo bucking horses.