CHALLENGING CASES IN INTERNAL-MEDICINE - WHATS YOUR DIAGNOSIS

A 9-YEAR-OLD spayed mixed-breed dog was presented to the referring vet erinarian for evaluation of paraparesis that had begun suddenly severa l hours earlier. The paraparesis was not thought to be clue to trauma. The Labrador retriever-springer spaniel mix weighed 46.2 lb (21 kg). Its vaccinations were current, and it had been receiving oral predniso ne (unknown dose) once a day for skin allergies. The referring veterin arian's tentative diagnosis was intervertebral disk disease. The dog w as given 16 mg of dexamethasone intravenously, and the oral prednisone was increased to twice-daily administration. The paraparesis resolved but recurred three weeks later as oral prednisone was decreased to on ce-daily administration. A second dexamethasone injection was given, b ut improvement was not observed until the oral prednisone was again in creased to twice-daily treatments. Even then, only minimal improvement was noted. The dog was referred ed to the Washington State University Veterinary Medical Teaching Hospital (WSU-VMTH) for evaluation of bil ateral hindlimb weakness.