A nine year-old male castrated Cocker Spaniel was referred to the Cornell University Hospital for Animals (CUHA) with a brief history of vomiting, lethargy, anorexia, painful abdomen, elevated liver and biliary enzymes, elevated cholesterol, and a leukocytosis. A presumptive diagnosis of a biliary mucocele with a probable gallbladder rupture was made via ultrasound and was confirmed via abdominal exploratory laparotomy. A cholecystectomy was performed. The patient recovered from surgery with few complications. Liver and biliary enzymes, cholesterol, and bilirubin levels were normalizing by two days post-surgery. The patient was discharged six days post-operatively with instructions to continue on Ursodiol and recheck the chemistry panel in a few months time to monitor liver and biliary enzymes.