A 7 year old spayed female Labrador Retriever presented to Cornell University Hospital for Animals’ (CUHA) Orthopedic Service for progressive hind limb lameness/paresis two weeks in duration. She was diagnosed with hip dysplasia as a younger dog. She was treated with deracoxib and dexamethasone, but only responded transiently to the latter. Upon presentation to CUHA she was paraplegic with absent pelvic limb proprioception. Pain was present at the level of T10-T11. A complete blood count revealed thrombocytopenia and a stress leukogram. The chemistry panel showed an increase in liver enzymes. Urinalysis was unremarkable. Thoracic radiographs revealed no obvious lesions. Differential diagnoses included, in order of priority, fibrocartilaginous embolism (FCE), neoplasia, intervertebral disc disease (IVDD) and infectious disease (e.g. neospora, rabies). An abdominal ultrasound was conducted the following day and did not disclose any neoplasia. An MRI showed a large lesion in her spinal cord suggestive of an infarct, but no evidence of compression. A sample of cerebrospinal fluid (CSF) was suggestive of a primary central nervous system disease. These results ruled out IVDD and supported FCE or neoplasia as the top differentials. Nine days after admission, the patient’s lung sounds were increased and she had moderate difficulty breathing. Thoracic radiographs did not reveal overt signs of aspiration pneumonia, but this was the presumptive diagnosis. She was placed on oxygen, started on enrofloxacin and ampicillin with sulbactam and treated with nebulization and coupage. The following morning, she began to show vestibular signs. Later that morning, she had a seizure, which was treated with diazepam, but seizures recurred. The owners elected euthanasia later that day. Her body was submitted for necropsy, which ultimately revealed CD3+ intravascular neoplastic cells, consistent with intravascular T cell lymphoma. Neoplastic cells were identified in sections of the brain, spinal cord, liver, stomach and lung. This is a rare neoplasia that is reported in the dog, and is also described in humans. This neoplasia is often neurotropic in nature; however, the mechanism of this tropism is currently unknown.