Abel Harris is a 4 1/2 year old mixed breed dog that was treated by the Oncology Service at Cornell University Hospital for Animals (CUHA) beginning in November 2006 for a stage Vb B cell lymphoma. Abel had been seen in October 2006 by the Neurology Service at CUHA and at that time a left head tilt, mild left sided Horner's Syndrome, mild masticatory muscle atrophy and left sided facial paralysis were noted; a tentative diagnosis of left peripheral vestibular disease was given. Abel's owners initially declined an MRI for further evaluation, but later scheduled one when they noted progression of his muscle atrophy. One week before the scheduled appointment, Abel developed signs of lethargy and abdominal distension, and his owners brought him into the CUHA Emergency Service for evaluation.