Poor nutritional status of septic, traumatized, or pre- and postsurgical equine patients is clearly associated with increased morbidity and mortality. Tissue repair and replacement, immunocompetence, and disease-related increases in energy requirements are three of many critical nutritional considerations in managing compromised and seriously ill patients. Although some patients can be maintained on enteral diets, many are unable to tolerate or safely receive any form of enteral support. For these patients, parenteral nutrition is a proven way to minimize such unwanted complications as secondary infections, sepsis, delayed wound healing, and critical weight loss. Since the mid-1980s, the development of highly efficacious and safe products and procedures has allowed veterinarians to administer parenteral nutrition admixtures by jugular, lateral thoracic, or cephalic veins in private practice and institutional settings.