: Subtle cues like dilated pupils, ear position, or a twitching tail often signal fear or irritation.

: Understanding species-specific "normal" behavior (ethograms) allows veterinarians to identify "abnormal" deviations—such as apathy or stereotypies like bar biting—as early indicators of disease. Welfare-Centric Handling

In veterinary science, behavior is often the first clinical sign of a medical issue. Animals cannot verbalize their pain or discomfort, so they communicate through actions.