This case report describes the occurrence of clinically significant osteochondrosis of the seventh lumbar vertebra in a 10-year-old, female Beagle with progressive monoparesis, lumbosacral pain and urinary incontinence. A presumptive diagnosis was made using radiography and computed tomography. The dog was surgically treated by a dorsal laminectomy and the detached bone fragment was removed. A postoperative computed tomography scan demonstrated the complete removal of the osteochondrotic tissue. Although the dog recovered remarkably after surgery, she developed a clinical relapse after several weeks. The owners declined further diagnostic tests and the dog was euthanized. Histopathological examination of the removed tissue was in agreement with a diagnosis of osteochondrosis of the seventh lumbar vertebra
