[Lumbosacral instability. The cauda equina compression syndrome in dogs].

The literature review includes a short anatomical description of the lumbosacral area, etiology, symptoms, diagnosis and therapy of CECS. Two hundred and twenty-seven large-breed dogs were examined clinically, neurologically and radiologically for diseases of the lumbosacral area. Radiological findings, such as dorsal dislocation of L7, spondylosis deformans, sloped craniodorsal contour of S1, sclerosis of the cranial plate of S1 as well as narrowing and increased density of the intervertebral foramen L7/S1 were compared with clinical and neurological results. In 15 dogs dorsal dislocation of L7 by 1 to 8 mm was found. An extended position proved to be more successful in demonstrating that finding than the flexed one. All other pathological changes were found either individually or in combination in patients with lumbosacral spondylolisthesis. One hundred and thirty-six dogs showed no sign of dorsal dislocation but all the other described changes. All detected changes have to be interpreted as instability of the lumbosacral area and resultant chronic and degenerative pathological processes. A definite correlation between spondylolisthesis of L7/S1 and compression of the cauda equina could not be found on plain radiography.