Baron, an eight year old male Labrador Retriever, first presented to Cornell University Hospital for Animals' Small Animal Internal Medicine service on July 14, 2004 for evaluation of a sudden onset left-sided head tilt of five weeks duration. Clinical signs began on June 10, 2004, and when Baron was evaluated by his referring veterinarian two weeks later, he also had a narrowed left palpebral fissure, decreased left menace response, and sagging left ear. The differential diagnoses included idiopathic, traumatic, or neoplastic causes, and Baron was referred to Cornell for further evaluation. On presentation, Baron was bright, alert, and responsive. The signs of left sided facial paralysis had resolved, and the only neurologic signs were a left sided head tilt, leaning to the left, and hesitation when turning to his left. Incidental pain was noted on manipulation of the right coxofemoral joint, attributed to an old traumatic injury. Bloodwork was unremarkable except for hypophosphatemia (1.9 mg/dL) attributed to respiratory alkalosis from panting. Urinalysis revealed alkalinuria, isosthenuria, pyuria, and frank blood. Preputial discharge was noted during the free catch collection of the urine, so a cystocentesis was performed and the urine was submitted for culture. The culture was negative for bacterial growth, so Baron was diagnosed with balanopisthonitis, and his signs resolved with a course of oral baytril. However, the results of these diagnostics could not be linked to his clinical signs