The hypothalamic-pituitary-adrenal (HPA) axis governs how an animal responds to threats. In a veterinary setting, a seemingly “aggressive” cat is often a cat in a state of toxic hyperarousal: cortisol levels can remain elevated for 48–72 hours after a single clinic visit. This is not “bad temperament”; it is a neuroendocrine storm.
Veterinary science has learned to measure this not just in blood tests, but in behavioral markers: These signs are diagnostically equivalent to tachycardia or
These signs are diagnostically equivalent to tachycardia or tachypnea—they are vital signs of a different color. during a veterinary exam or hospitalization)
Stress is a physiological response that directly impacts health. When an animal experiences fear or anxiety (e.g., during a veterinary exam or hospitalization), the body releases cortisol and adrenaline. but in behavioral markers:
A revolutionary shift in modern veterinary science is the move away from physical restraint (scruffing, choke collars) toward cooperative care.
Perhaps the most fascinating frontier in this intersection is psychoneuroimmunology—the study of how the brain, behavior, and immune system interact. In veterinary science, we now know that behavioral issues can cause organic disease, and organic disease can manifest as behavioral symptoms.