The Spokesman-Review reports the officer was taken to a hospital for treatment after being bit on his arms and legs on Wednesday afternoon.
He was at the property to return keys to the homeowner's son, who lives there.
Spokane Valley police spokesman Craig Chamberlin says he's not sure if the officer saw the dog in the yard before he entered. Beware of dog signs were posted in the yard.
The homeowner wasn't at home at the time of the shooting. Brad Beck wondered why the officer didn't use mace on the dog and why the dog didn't get immediate medical treatment.
Beck says that the dog was a Husky mix. Police say the dog was a pit bull mix.