ABSTRACT
Physiologic signs of acute pain include increased blood pressure, heart rate, and peripheral vasoconstriction that manifest it as blanched mucus membranes. Respiratory rate often increases and muscle splinting may occur if pain is localized within the thorax. Responses to pain vary among species, but a variety of behaviors and signs are consistent with ongoing painful conditions. Alterations in normal vocalization patterns and attention-seeking behaviors are common. Dogs often whine or whimper while cats groom, growl, or purr. Facial expressions and body posture can be quite revealing as dogs may have a fixed stare and arching posture whereas cats may squint their eyes and refuse to move. Pain can reduce appetite and food intakes, alter voiding behaviors, and reduce grooming behaviors so that the patient appears disheveled. Given the complexity of pain perception, behavioral signs of pain are unique for each animal and may be best identified by the animal's owner.
