A police officer sent out on a complaint of a “vicious, loose dog” on Willoughby Avenue shot and killed the animal this afternoon after it lunged at him, the police said. The police said there was a 911 call at 1:29 p.m. about the dog, who was in front of 54 Willoughby, near Clermont. When the dog lunged at the first officers who arrived at the scene, one of the officers shot the dog once in the chest, killing it instantly, the police said. The Breaking News Network, a service maintained by people who monitor police scanners, said the dog was a Rottweiler, but the police public information office did not know the breed. No one else was injured.