Calcium dysregulation in small animals: When is it an emergency?

Calcium is essential for neuromuscular signaling, cardiovascular stability, and metabolic regulation. Disturbances in calcium homeostasis can exacerbate critical illness in small animal patients, whereas more profound abnormalities are associated with life-threatening complications. Although not frequently encountered, both hypocalcemia and hypercalcemia require rapid recognition and targeted therapy in an emergency setting. This article reviews the fundamental principles of calcium regulation, outlines the major etiologies and clinical features of disordered calcium balance, and provides an evidence-based approach to acute management. Practical considerations for monitoring, fluid and drug therapy, and supportive care are emphasized. Finally, we present novel and experimental interventions under evaluation in both veterinary and human medicine, highlighting areas in which future research may improve treatment options for animals.