Although bacterial pyoderma is among the most commonly encountered dermatologic conditions in dogs, some cases present diagnostic challenges even to experienced clinicians. This article presents several unusual manifestations of pyoderma, including bullous impetigo, superficial spreading pyoderma, mucocutaneous pyoderma, and post-grooming furunculosis. Conditions mimicking pyoderma, including juvenile cellulitis, immunomodulatory-responsive lymphocytic-plasmacytic pododermatitis, and pemphigus foliaceus are also described. Diagnostic techniques used for diagnosing and characterizing pyoderma are also discussed.