The substantial increase in our collective knowledge of pain physiology and pharmacology over the past decade has had a significant effect on the practice of clinical veterinary medicine. An overview of the basic anatomical and physiologic components of nociceptive processing is presented, as well as a discussion of the sensitizing events that occur within the nervous system in acute and chronic pathologic pain states. The unique features of visceral and neuropathic pain are also outlined. With the goal of improving the success of our therapeutic interventions, the final section is devoted to the various classes of analgesic drugs and techniques, and how they are best incorporated into pain management strategies.