Despite a multitude of advances in our understanding of veterinary neurology, peripheral neuropathy remains one of the most challenging areas with regard to recognition, diagnosis, and therapy. Often the exact etiology of a peripheral neuropathy remains elusive despite extensive biochemical, toxicological, electrophysiological, and histopathological evaluation of muscle and nerve biopsies. Despite these difficulties, the early clinical recognition of peripheral neuropathy, followed by a logical sequential diagnostic evaluation, is essential to have a better understanding of the disease process and to hopefully come closer to a specific etiologic diagnosis. Only then can appropriate therapy be instituted in order to attempt to halt or, in some cases, reverse the peripheral nerve dysfunction. This article outlines a logical approach to peripheral neuropathy in the dog, followed by a detailed discussion of its most common causes.