Massive osteolysis in a dog resembling Gorham's disease in humans.

An eight-month-old mixed-breed dog was presented with a history of sudden onset pelvic limb lameness. Radiographic and computed tomographic examinations demonstrated an osteolytic process involving the lumbar spine and pelvis. A comprehensive work-up including serial radiographic skeletal survey, biopsy, routine laboratory investigation and evaluation of parathyroid hormone (PTH) and 25-hydroxy-vitamin D levels failed to reveal any underlying cause for the osteolysis. Conservative treatment using the bisphosphonate drug alendronate and oral analgesic medications resulted in a return to nearly normal long-term function, despite massive lumbar and pelvic osteolysis. The clinical, radiological and histopathological features in this dog are reported, and similarities with the human condition known as Gorham's disease are discussed.