This makes it difficult to identify the patient population most likely to benefit from nutritional support. Five clinically used indicators of nutritional status (serum albumin, hematocrit, hemoglobin, total peripheral lymphocyte count, and a “body condition” score) were evaluated on admission for 105 dogs that wer hospitalized at the Veterinary Hospital of the University of Pennsylvania for serious illness or major surgery. The prognostic relationship between these admission measurements and clinical outcome (discharged vs. died in hospital) was examined. Abnormally low serum albumin, hematocrit, and hemoglobin were associated with poor ultimate clinical outcome (p< 0.01). Hypoalbuminemia has a strong association with protein-calorie malnutrition although serum levels of albumin can be affected by many non-nutritional processes. Admission serum albumin level can predict clinical outcome and may identify a population of critically ill canine patients that could benefit from nutritional support.