The Chautauqua County Sheriff's office says the impostor is going to homes in the towns of Pomfret and Portland and saying he's the Pomfret warden.
He then tries to confiscate or impound residents' dogs. It wasn't initially known if he's gotten away with any animals.
Deputies said Wednesday the man in his early- to mid-30s drives a small brown sedan.
They're asking anyone with information to contact them at 753-4232 or Sgt. Peter Pett at 753-4498.