Splenic myelolipoma is a rare tumor in dogs with an unclear origin. A male 13-year-old Schnauzer dog was presented because of a bump on the left side of the abdomen. Clinical examination and abdominal ultrasound revealed a mass in the spleen. A total splenectomy was carried out, and histopathology revealed a splenic myelolipoma. Before surgery, the patient showed high serum alanine aminotransferase levels, which returned to normal eight months after the resection. Unfortunately, the postoperative follow-up showed increased serum cholesterol and triglyceride levels, suggesting liver compromise. This is the first report of a splenic myelolipoma in Colombia.