Stable heart rate, arterial pressure, oxygen saturation, and end-tidal carbon dioxide can coexist with physiologically important risk because each variable samples only part of oxygen transport, organ blood flow, ventilation, thermal balance, nociceptive stress, and recovery. This article develops an original non-empirical, physiology-guided framework for organ protection during canine and feline anesthesia. The analysis separates measured stability from inferred physiological adequacy and distinguishes pressure from flow, oxygenation from ventilation, global variables from organ-specific vulnerability, an isolated deviation from accumulated exposure, and intraoperative correction from verified recovery. The proposed framework organizes perioperative assessment around parallel domains of oxygen delivery and perfusion, ventilation and gas exchange, temperature and metabolic demand, analgesia and neuroendocrine stress, duration of physiological insult, and recovery-phase surveillance. These domains are interpreted against patient susceptibility, procedure, anesthetic state, measurement credibility, and temporal trajectory. A normal value in one domain does not compensate for unresolved risk in another; corrective action should address the inferred mechanism and be followed by multidomain reassessment. Organ-specific warning states are treated as graded interpretations rather than validated scores or universal thresholds. The framework is intended to improve clinical reasoning, communication, and research design, not to claim prospective prediction or demonstrated outcome improvement. Important boundaries include limited direct veterinary organ-outcome evidence, heterogeneous definitions, device and site effects, confounding by illness and treatment indication, and restricted transferability across species, breeds, procedures, and practice resources. Prospective validation must link defined physiological exposures and responses to organ-specific and recovery outcomes.
