This case study explores whether an individual can sustain Posttraumatic Stress Disorder (PTSD) subsequent to witnessing serious injury to his companion pet. While walking his dog, a 62 year old man was struck by a car. While lying on the road, he was emotionally traumatized by the serious injury to his companion pet dog. Later, he experienced significant flashbacks of his dog being injured, hypervigilance, avoidance of the injury site and leaving his house, and fear that his dog would be reinjured among other symptoms. The case study is analyzed relative to the Diagnostic Statistical Manual of Mental Disorders, 4 th edition (DSM-IV-TR) diagnostic criteria for PTSD. Currently the DSM-IV-TR limits the PTSD diagnostic Criteria A to people only, using a specific requirement that the traumatic injury take place to a "self" or "others" (American Psychiatric Association, 2000). This case study suggests an expansion of the PTSD's Criteria A to include additional stressor events, such as traumatic injury or death of a companion pet.