Pain control is a key element of animal welfare, and behavior scales are often used for quantification. Personality, defined as individual differences in behavior that are stable over time and across contexts, can affect behavior assessment scales. This study investigated whether extraversion and neuroticism (as measured by the Monash Canine Personality Questionnaire-Revised) are associated with differences in behavioral and physiologic responses to pain induced by routine neutering in dogs. Results indicated that more highly extraverted dogs had significantly higher pain scores, whereas neuroticism was not associated with physiologic or behavioral pain responses. Owners’ ratings of their dog’s pain tolerance were not found to be a reliable predictor of pain response.