No one contested that a now-deceased dog named Depot, the pet of Sen. John Warner (R-Va.) and his former wife, actress Elizabeth Taylor, bit a Massachusetts pediatrician who was visiting Warner's 1,850-acre farm in the horse country near Middleburg, Va., in 1980.

But after 15 minutes of deliberation yesterday, a federal jury in Alexandria determined that Depot's owners were not to blame for the wound, which Dr. Edward F. McGrath said turned his right ankle into "raw hamburger."

McGrath, who sued the couple for $250,000, said the bite left him hospitalized for eight weeks and cost him income, $18,000 in medical fees and peace of mind.

"The great American jury system has vindicated the honor of my late departed friend, my dog, Depot," Warner said in a statement issued after the verdict.

In his lawsuit, filed in U.S. District Court, McGrath alleged Warner and Taylor had violated a Virginia law that requires owners to restrain animals known to be vicious.

In testimony at the suit's trial yesterday, Warner spoke warmly of Depot, a diminutive black and brown mongrel with a splash of white on the throat, who was pressed on Taylor by a stranger in Washington's Union Station.

"He was a mutt in every sense, but a lovable one," Warner told the jury. "He was a simple little household pet. He was there because we loved him and took him in."

According to Warner, Depot had no record of viciousness before the biting.

Taylor, currently acting in a play in New York, did not appear at the trial. She was married to Warner at the time of the dog-biting incident but the two have since been divorced.

Depot later was run over on the farm grounds and killed by a car driven by a farm employe's son.

McGrath, 69, testified that he went to Warner's farm, Atoka, in 1980 for a Christmas visit with his niece, Kathleen Doyle, who rented a house and barn on the farm grounds and operated a horse-training business there.

While walking on a farm road on the afternoon of Dec. 18, McGrath said, he was attacked without warning by Depot. "He sneaked up behind me. He didn't yelp or bark or make any sound," McGrath said during a break in the trial. The dog seized his right ankle and inflicted multiple wounds, he said.

The wounds later became infected, McGrath testified. He spent eight weeks in a hospital, rested at home for another two and incurred medical bills of more than $18,000. His absence cut deeply into his income from his pediatric practice in Milton, Mass., he said, lost him patients and caused him mental anguish.

In testimony, Doyle said Depot once nipped at the hooves of a horse she was riding and made threatening movements toward her when she dismounted to chase the dog away. Depot also once got into a scrap with two dachshunds she kept, Doyle said.

Despite incidents like this, McGrath's attorney argued, the dog was allowed to run free around the farm and no signs were posted warning of a dangerous animal. This constituted negligence on the part of Taylor and Warner, the attorney contended.

Three employes of the farm, called to testify in Warner's defense, said that Depot had no reputation for viciousness. "Everybody loved him. He was very playful," said Jerry Ann Dade, who described herself as a domestic employe who did cooking and cleaning for the family.

She told the jury Depot would lie around on a couch in the library and wait for Warner and Taylor at a window when they were expected on weekends.

McGrath's attorney said no decision had been made on a possible appeal.