Animals cannot verbally communicate pain, and many species actively hide it. Learning to recognize the behavioral and physiological signs of pain is one of the most important skills for anyone responsible for animal care.
Pain recognition is the gateway to pain management - suffering that is not recognized cannot be treated. The evolutionary pressure on prey animals to hide pain means that owners and veterinarians routinely underestimate the degree of pain their animals experience. A rabbit sitting quietly in the back of its enclosure may be in agony; a horse continuing to work may have bone stress fractures; a cat eating normally may have severe dental disease. The development and validation of species-specific pain scales and grimace scales has been one of veterinary medicine's most important welfare advances. These tools translate what animals cannot say into information that enables evidence-based pain management.