WHITEFISH, Mont. (AP) _ Searchers Tuesday looked for a U.S. Customs and Border Protection narcotics dog that became separated from his handler during a patrol, chased wildlife in the forest near the U.S.-Canada border northwest of here and disappeared.

Eddie vanished Monday afternoon after the handler, a patrol agent, lost his balance on slippery ground and let go of a leash to avoid jerking the German shepherd, said James Bunner, supervisory agent for the patrol in Whitefish. A search began immediately, continued overnight and was ongoing late Tuesday afternoon.

Bunner said that after the 6-foot leash was released, Eddie moved a couple of feet and alarmed wildlife, which fled. Then Eddie gave chase. He did not heed the agent's call to return.

Agents were deployed in the search, which included use of horses and all-terrain vehicles. The number of people searching simultaneously has been six to eight, Bunner said.

The dog, trained not only to detect narcotics but also humans in concealed places such as railroad boxcars, is one of two assigned to Customs and Border Protection in Whitefish, a resort town in northwestern Montana. Agents use the dogs to sniff for drugs at U.S.-Canada border crossings.

They are ``a wonderful working tool that the agency has a lot of time, energy and financial resources in,'' Bunner said. ``They are one of the team.''

He declined to release the name of the agent to whom the dog was assigned. They were together about a year and established a bond, Bunner said.

Eddie, about 70 pounds, was not trained to be aggressive.

He disappeared near the Montana-British Columbia border, about 68 miles northwest of Whitefish. Bunner said he did not know whether it was deer or other wildlife that the dog pursued.

Eddie, 2 1/2 to 3 years old, has a long coat and is able to withstand the mid-20s temperatures that chilled northwestern Montana early Tuesday, Bunner said. He is black and tan, and wore a chain collar with both a rabies tag and a tag bearing his name. Inside his right ear, Eddie has a five-digit tattoo.

Bunner said he was not sure whether Eddie came from a European breeder, as do many of the agency's dogs. Some cost about $4,500, he said. Training takes place at the patrol's canine center in El Paso, Texas.

Border protection officials asked that anyone with information about Eddie's whereabouts call (406) 862-2561. Caution should be used in approaching him, because he may be injured or frightened, the agency said.