An approximately eight year old male castrated Pug was initially seen at his primary care veterinarian for suspected cystic calculi after having two to three incidents of inappropriate urination with crystalline appearance. Obtained off the street as an adult in 2007, the patient had been clinically healthy apart from a low body condition score of 4/9 and fleas, when found. History of intermittent vomiting and prolonged recovery from anesthesia post castration and dental extractions was noted but never investigated further since the patient was apparently healthy. Due to inappropriate elimination, the patient was seen by a primary care veterinarian in March 2010 for diagnostic workup. Blood work and abdominal radiographs were performed. The complete blood count (CBC) was unremarkable except for a mild microcytosis. The biochemical profile revealed low normal urea nitrogen and cholesterol. Urinalysis showed alkaline urine with multiple struvite and amorphous crystals. Urine culture was negative. Two view abdominal radiographs were negative for calculi but showed subjective evidence of microhepatica, with the gastric axis being shifted cranially. Based on the radiographic findings, serum bile acids were recommended and showed increased concentration both pre- and post-prandial. Ultrasound examination was performed and confirmed negative cystic calculi but microhepatica was apparent, with overall liver parenchyma being normal. No obvious portosystemic shunt (PSS) was evident on ultrasound but due to increased serum bile acid concentrations, the patient was placed on Hill’s L/d diet and lactulose. He was subsequently presented to the Internal Medicine Service at Cornell University Hospital for Animals in April 2013 for work-up of a PSS. Upon presentation, he was bright, alert and responsive. Physical examination disclosed a body condition score of 6/9 and mild dental disease. History of vomiting had resolved since being fed the Hill’s L/d diet exclusively and no clinical signs associated with PSS were ever noticed by the owner. Repeat bloodwork and transcolonic scintigraphy was completed. The CBC showed mild neutrophilic leukocytosis and lymphocytosis. The biochemical profile revealed decreased blood urea nitrogen and albumin. Pre- and post-prandial serum bile acids were significantly increased but Protein C (PC) was normal. Urinalysis was unremarkable. Transcolonic nuclear scintigraphy was negative for PSS and a presumptive diagnosis of hepatic microvascular dysplasia was given. Owner declined liver biopsy since patient was clinically normal. At present, the patient is doing well and continues to eat Hill’s L/d exclusively with occasional treats.