Three dogs that presented to the emergency service in severely emaciated body conditions were admitted to the hospital for monitoring and refeeding. During their hospitalization, all three dogs developed electrolyte derangements or required supplementation to prevent hypophosphatemia and hypomagnesemia. Additionally, all dogs developed hyperlactatemia, which was suspected to be secondary to thiamine deficiency. Two dogs were reported to have cardiac abnormalities, including cardiac arrhythmias, systolic dysfunction, and spontaneous echogenic contrast. These cases highlight the complexity of refeeding syndrome and its associated complications that extend beyond electrolyte deficiencies.