Hypoalbuminemia is common and associated with a variety of disease processes, including those leading to systemic inflammatory response syndrome, gastrointestinal disorders, hepatic disorders, and glomerular diseases. Some animals develop clinical signs directly caused by low serum albumin concentration. There is strong evidence that hypoalbuminemia is associated with worse outcomes; however, evidence justifying albumin supplementation is lacking. Severe adverse events are frequently reported with administration of human serum albumin and there is little evidence of benefit from other products. Most patients will not require administration of albumin-containing products. Clinicians should consider early enteral nutritional supplementation in critically ill patients.