EJCAP Online 22(4), December 2012, English
8 Lower back pain in dogs
The nerve root bundles extending from the lumbosacral section of the spinal cord are called “cauda equina fibres” (latin: horses tail). The spinal cord narrows at the level of the last lumbar vertebra forming the conical shaped ending of the spinal cord where the cauda equina fibres originate. Compression of the described nerve fibres leads to characteristic clinical signs. Underlying primary malformation and secondary degenerative changes that lead to disease should be differentiated. In the course of degenerative changes the intervertebral disc plays a major role. Degenerative changes lead to an alteration of the intervertebral disc composition and are frequently associated with herniation of intervertebral disc material into the vertebral canal. The degree of nerve root compression is dependent on the diameter of the vertebral canal at the involved level. Multiple predisposing factors lead to stenosis of the vertebral canal. The disease caused by ageing of the disc and concurrent stenosis is called “degenerative lumbosacral stenosis”. Degenerative lumbosacral stenosis (DLSS) is part of acquired lumbosacral disorders and affects most commonly medium and large dog breeds. A congenital form of lumbosacral stenosis is represented by the so called idiopathic stenosis which affects small breeds more commonly. Despite this the German Shepherd dog shows signs of idiopathic stenosis. Other reasons for acquired lumbosacral stenosis are discospondylitis or neoplasia.
Klinik für Kleintiere der Justus-Liebig-Universität Gießen,
Kerstin Amort graduated in 2007 from the Faculty of Veterinary Sciences in Giessen (Germany). She is currently Resident of the European College for Veterinary Diagnostic Imaging.
She is member of the European Association of Veterinary Diagnostic Imaging (EAVDI) and of the European Society for Magnetic Resonance Imaging in Medicine and Biology (ESMRMB). Her special interest in research is focused on hereditary disorders of the skeleton in dogs and cats with special regard on the Cauda equina compression syndrome.
Kerstin: “The broad spectrum my work offers every day including clinics, research and education is fantastic.”
Ventrodorsal radiographs of the lumbosacral junction:
Figure A shows a normal finding. Figure B shows an asymmetrical lumbosacral transitional vertebra (arrow).
Lateral radiograph of the lumbar spine and lumbosacral junction of a dog: Degenerative changes of the spine include severe ventral spondylosis (arrows), deformation of the endplates and increased sclerosis of the endplates.
T2 weighted sagittal MRI examination of the lumbar spine and lumbosacral junction (cranial to the left): The red arrows show intervertebral discs with moderately reduced central nucleus pulposus signal. The white arrow points to the intervertebral disc of the lumbosacral junction that shows a complete loss of the hyperintense (bright) nucleus signal and is completely hypointense (dark).
T2 weighted dorsal MRI examination of the lumbar spine and lumbosacral junction of a dog (cranial to the top): The hypointense (dark) cauda equina fibers are well delineated (arrows) and embedded in the surrounding hyperintense (bright) fat.
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by Kerstin Amort, Nele Ondreka and Bernd Tellhelm
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Volume 22(4), December 2012 SPECIAL ISSUE
Several studies report the German Shepherd Dog (GSD) as the most frequently affected breed of degenerative lumbosacral stenosis. A study of the lumboascral intervertebral disc (in 110 GSDs and 52 dogs from other breeds) implied a genetic predisposition in this breed for primary disc degeneration.
Slideshow of radio-graphic and MRI examinations of dogs with degenerative lumbosacral stenosis.
Lower back pain in dogs
Cauda equina compression syndrome
The nerve root bundles extending from the lumbosacral section of the spinal cord are called “cauda equina fibres” (latin: horse's tail). The spinal cord narrows at the level of the last lumbar vertebra forming the conical shaped ending of the ...