For decades, the practice of veterinary medicine focused primarily on the physiological: the broken bone, the infected tooth, the elevated white blood cell count. However, in the last twenty years, a quiet but profound revolution has taken place in clinics and research labs worldwide. The rigid line between "physical health" and "mental health" in animals has begun to blur.
Behavioral changes are often the earliest, most subtle indicators of underlying disease. A condition called "latent pain" is a prime example. An arthritic horse may not visibly limp, but a behaviorist will notice its reluctance to lie down and roll. A cat with dental disease may not stop eating, but it might start dropping food or chewing only on one side of its mouth. For decades, the practice of veterinary medicine focused

