A 3-year-old castrated male mixed breed dog presented to the Cornell University Hospital for Animals Emergency Service on August 3rd, 2013 with a 5-day history of acute ascending tetraparesis. On July 28th, the patient was ataxic in the pelvic limbs after playing with other dogs. The following morning he appeared weak in all limbs, then collapsed and was subsequently unable to stand. The patient was presented to his primary veterinarian that day, and physical exam revealed non-ambulatory tetraparesis with absent proprioception and motor in all 4 limbs. No discomfort was elicited on spinal palpation. A 4DX snap test was positive for Lyme disease and Ehrlichia. In-house blood work, thoracic radiographs, and cervical spinal radiographs were unremarkable. The patient was hospitalized overnight at the primary veterinarian’s office and was started on doxycycline and a short tapering course of prednisolone. His neurologic status remained static, however he was eating and drinking well on his own and thus was discharged to the owner's care on July 30th. Following discharge, the patient remained non-ambulatory and recumbent at home with no appreciable change in his neurologic status. The patient then became reluctant to eat or drink, at which point he was referred to Cornell for further evaluation.