DETROIT, Maine — A search for a little white dog that ran away as she and her owner were arriving at a grooming appointment in Detroit was suspended Sunday, after the dog’s barks could no longer be heard and volunteers were unable to find any trace of her.

The effort to find Bonnie, a 9-year-old West Highland white terrier, was somewhat unusual, in that it involved, among other things, the use of Down East Emergency Medicine Institute’s drone, which is equipped with high-resolution and infrared imaging technology.

The drone has been used in several missing person cases in the region, but until now it had not been used in an animal rescue.

Richard Bowie, DEEMI’s operations director, said the missing dog case provided training opportunities for its volunteer members.

The drone was deployed in the River Road area Friday and Saturday, but the search for Bonnie was discontinued Sunday decision, Bowie said.

Bowie said he hoped the fact that barking could not longer be heard meant Bonnie somehow got out of the bog on her own.

When aerial search efforts began Friday, Bonnie had not been seen since May 11, when she make a break for it, got away from her elderly owner and ran off into a nearby swampy wooded area, according to Cassandra Melanson of Palmyra, a friend of Bonnie’s owner, Pearl Jones of St. Albans.

Melanson and others worried Bonnie was either injured, stuck or otherwise unable to make it out of the woods on her own.

Melanson and other searchers believed Bonnie was still in the woods because they could hear her barks from off in the distance. Efforts to retrieve her were hindered, in part, by the boggy terrain and large wild animals.

Melanson said Bonnie was the mother of her own Westie, who died last June and that she and her mother, Darlene Badger, used to own Bonnie.