MLS Master Class - Veterinary Imaging
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Practical treatment:  The Vertebral Column

Carl Gorman BVSc MRCVS

Key words :    Laser, Spine, Spondylosis, lumbo-sacral syndrome, intervertebral disc



Disorders of the vertebral column are common in small animals.  Intervertebral disc disorders, muscular problems and developmental diseases are common in dogs, while cats are more prone to traumatic conditions.  Spine associated problems can be a source of significant and chronic pain, affecting a patient's mental state as well as interfering with mobility.  Diagnosis of the problem is important.  A multi-modal approach to management is usually required which might involve surgery, drugs for pain relief and muscle relaxation, physiotherapy as well as non-drug analgesia such as can be provided by the MLS laser.


The vertebral column is normally divided anatomically into 5 areas: cervical, thoracic, lumbar, sacrum and caudal or coccygeal (Fig 1).  The sacrum consists of several fused vertebrae which form a unit and which articulate with the pelvis to form the roof of the pelvic canal.  The other vertebrae are individual bones which articulate with the vertebrae on either side. 


Figure 1 Sections of the canine spine

Cats and dogs have the following numbers of vertebrae:

                Cervical                  7

                Thoracic               13

                Lumbar                   7

                Sacral (fused)          3

                Coccygeal            20-23

The articulations between vertebrae are of two types:

                Cartilaginous joints:  These are a direct articulation between the vertebral bodies and consist of thick flexible intervertebral discs.  They in turn are made up of two parts:

                                  Nucleus pulposis: a softer portion contained in the centre of the disc

                                  Annulus fibrosis:  tough bundles of fibrous tissue which form a ring around the nucleus, containing that softer material.

                Synovial joints : These are found between the facets of the vertebral arches.

The vertebrae articulate so that they form a bony tube extending from the skull to the sacrum.  The spinal cord is housed in this tube and protected by it.  The spinal nerves leave the spinal cord via the spaces between the vertebrae.  They are paired, with the sensory portion leaving the dorsal root of the spinal cord, while the motor fibres leave via the ventral root.

The muscles of the spinal columns are epaxial and hypaxial muscles

Epaxial muscles

                These are extensors of the spine and lie dorsal to the transverse processes.  They are arranged in 3 columns:

Lateral column - the iliocostalis muscles arise from the ilium and the transverse processes of the caudal lumbar vertebrae to insert on the cranial lumbar vertebrae and the ribs.

Middle column - the longissimus muscles are the strongest and extend from the ilium and sacrum up to the head and neck.

Medial column - the transversospinalis muscles lie between the medial vertebral arches and the dorsal spinous processes.

Hypaxial muscles

                These are flexors of the vertebral column and lie ventral to the transverse processes of the vertebrae.

                They include:

                                Longus colli- extending from the cranial thoracic region to the atlas vertebra

                                Longus capitus- from the mid-cervical vertebrae to the skull

                                Scalenus- from the caudal cervical vertebrae to the first few ribs, which they stabilise

                                during respiration.

                               Internal and external intercostals -muscles of the thoracic wall

                               Internal and external abdominal oblique- muscles of the abdominal wall


Treatment of the vertebral column

Treatment of the spine following surgery is designed to reduce inflammation and oedema, thus reducing pain, while encouraging healing.  Conservative treatment of spinal conditions is used to reduce inflammation of the associated soft tissues, relieving pain and improving quality of life.

There is a tendency to try to avoid using back muscles when they are painful.  This can lead to disuse atrophy and weakness, which in turn reduces the support that these muscles provide to the spinal column, and therefore lead to increased pain.  Reducing pain the muscles and allowing controlled use is an important part of managing back pain.

Apply the laser to the paravertebral tissues on either side of the spine, treating both cranially and caudally to the lesion.  Point or scanning mode can be used.  Ensure that the paravertebral muscles are treated to reduce contracture.  Concentrate on any painful foci.

Trigger points associated with the spine may be found in the infraspinatus, the middle gluteal and anywhere along the length of the paravertebral muscles.

Examples of conditions of the spine

Spondylosis deformans is a non-inflammatory degenerative condition of the vertebrae, characterised by proliferation of osteophytes, or bony proliferation of the vertebral bodies.  Although it has been described as generally a pain free condition, the stimulus for the production of osteophytes is instability between the vertebrae.  Thus spondylosis develops where there is intervertebral disc disease or excess strain on sections of the spine.  Animals known to be affected should be carefully assessed for signs of pain and gait abnormalities. (Figs 2,3)


Figure 2 Bridging spondylosis in a dog affecting L2-3 and L3-4.  There is also spondylosis between L7-S ('lumbosacral syndrome')

Lumbo-sacral disease.  A degeneration of the lumbo-sacral intervertebral disc with associated bone proliferation and pain or reduced motor function in the hind limbs. (Fig 3)


Figure 3 Lumbosacral disease affecting a cat

Fractures or dislocations of the spinal column. (Figs 4,5)


Figure 4 Fracture - luxation.  Note the fracture of T13 in this dog causing disruption of the spine


Figure 5 Two fractured spinal processes in a cat

Intervertebral disc protrusion or extrusion. (Fig 6)


Figure 6 Compression of the spinal cord, demonstrated by myelography.  Note the compression of the spinal cord at L1-2 and L4-5.

Wobbler syndrome.  This term covers a group of conditions affecting the cervical vertebrae, often in large breeds such as Doberman or Great Dane. There may be anatomical abnormalities in vertebrae, or disc disease which leads to narrowing of the spinal canal and thus pressure on the spinal cord.  This leads to ataxia ('wobbling') and often pain.

Practical laser treatment of spinal conditions

If there are bony changes in the spine, ensure these are identified and localised with radiographs.  Concentrate on these areas using the small head and point mode.  After this, treat the paravertebral muscles using scanning mode.  If you have access to the larger ultra head, this can be used in either scanning or point mode to treat the muscles.  (Fig 7)


Figure 7 A cat receiving treatment to its back with an ultra head

You may be able to identify painful knots in the paravertebral muscles (trigger points).  Treat these using the trigger point setting.

Frequency of treatment

Treatments should be administered two or three times weekly depending on the clinical condition.

Programmes recommended

1)      Post surgery or for acute pain:

  • 'Post surgery', 'Acute inflammation' or 'Acute pain'
  • Normally use point mode.
  • Consider reducing intensity during the first 2 or 3 treatments (use 50% intensity rather than 100%).

2)      Conservative treatment of chronic conditions:

  • 'Chronic inflammation', 'Arthrosis' or 'Chronic pain'.
  • Use point mode over vertebrae/discs.

3)      Muscle contractures in the hypaxial and epaxial muscles

  • For acute cases use 'Acute pain'.
  • For chronic cases use 'Sprain/strain' or 'Muscle contracture'.
  • Use scan mode to cover the contracted area and surrounding tissue.

4)      Trigger points

  • Trigger point setting up to 3 times.