The secretaries of the Army and the Air Force have decided to ban the use of dogs and cats in biomedical and clinical research under their control, halting scores of experiments and leaving military researchers howling.

Air Force Secretary Verne Orr last week ordered that all dog and cat experiments at Air Force facilities or under Air Force contracts "be discontinued" immediately. The Army followed suit Tuesday.

The surgeon general of the Air Force, however, plans to appeal the order. "We need the dogs and cats in the type of research we're doing." said Pat Bragg, a spokesman for that office. "We've been using them for years. We've got ongoing programs."

Others in the military medical research community also expressed concern about the possible ramifications.

The Defense Department annually uses about 2,000 dogs and an unknown number of cats for medical research, according to a spokesman. The Army order will affect about 350 dogs and 135 cats; the Air Force had no figures available.

Bragg said the Air Force uses animals in a broad range of research projects involving cancer treatment, respiration, the affects of various drugs as painkillers and the uses of fluoride for teeth. An Army spokesman said his service uses dogs primarily in cardiovascular research and cats in neurological research, including a study to find antidotes for nerve gas.

Animal-welfare advocates, who have long advocated a search for alternatives to using animals in medical research, were surprised by the announcement. While they generally welcomed the decision, some were suspicious about the timing and the motive of directives that apply only to the most popular household pets, and not to the scores of other animals used for research.

"It's about time they banned the unnecessary and cruel use of animals," said Janet M. Huling, spokesman for the Humane Society of the United States. "We would like to see an immediate ban on all research that inflicts pain and suffering, and a department-wide review" of animal experimentation.

Dr. John McArdle, the Humane Society's director of laboratory animal welfare, added, "It's a rather amazing thing to happen. It was totally unexpected, and we didn't ask for it." McArdle said his group had been working to halt the use of animals in weapons testing -- particularly in controversial ballistics tests.

"I can't believe it!" said Alex Pacheco, head of the Washington-based People for the Ethical Treatment of Animals. "I can't believe the military medical research community would stand for it."

The directives come during a large-scale review of the use of animals for military research and training. Defense Secretary Caspar W. Weinberger ordered the review last year after a public outcry over DOD plans to shoot scores of dogs and other animals at a Bethesda facility to help develop ways of treating wounds.

Army and Air Force spokesmen said they could not confirm whether the new orders were a result of the review. But Bragg and others said the directives came after a Sept. 20 meeting between Weinberger and the three service secretaries.

A Navy spokesman said that Navy officials were aware of the directives and would comply with any department-wide policy.

The new directives also come after a national magazine, with the help of animal-rights advocates, has begun work on an article alleging that the Army was using dogs and cats in nerve gas experiments at the Aberdeen Proving Ground in Maryland.

Defense industry lobbyists also have been trying to head off an amendment to the defense appropriations bill that would ban the use of dogs and cats at wound laboratories such as the one in Bethesda.