Wobbler syndrome

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Radiograph of a dog with Wobbler syndrome, showing compression of cervical vertebrae[1]

Wobbler syndrome (cervical vertebral malformation malarticulation syndrome) is a congenital disease of dogs characterized by malformation and upward tilting of a cervical vertebral body, often C4 - C7.

This condition should be distinguished clinically from atlantoaxial subluxation which affects the atlas and axis vertebra and hemivertebra (which involves malformed vertebrae and scoliosis/kyphosis).

A breed predisposition is seen in Doberman, great Dane and Borzoi breeds. Although the cause of this condition is not entirely known, genetics and nutrition may play a role in the development of the defect. In some young dogs, excessive intake of a diet high in protein, energy, calcium, and phosphorus accelerates growth and may induce skeletal changes such as those seen in 'wobbler' dogs.

Clinically affected dogs present with characteristic ataxia, hemiparesis of the hindlimbs and a stumbling gait, with normal sensory reflexes, which may progress to hindlimb paralysis.

Diagnosis usually requires cervical myelography[2] or MRI imaging studies[3]. Degenerative changes affecting the articular process joints are a frequent finding in these patients. Features of this condition include cervical articular process joint degeneration, spinal cord compression, vertebral foraminal stenosis, intramedullary spinal cord changes and intervertebral disc degenerative changes[4]. Motor evoked potentials also reveal reduced cranial tibial muscle latency and amplitude in wobbler dogs[5].

Conservative treatment of disc-associated wobbler syndrome (e.g. long-term prednisolone therapy) is associated with a guarded prognosis and should only be considered in cases where all four limbs are not affected and no additional radiographic and/or myelographic abnormalities are detected[6]. However, other studies have shown that there is little difference between medical or surgical treatments in terms of outcomes in the long-term.

Surgery requires hemilaminectomy to alleviate spinal cord compression with or without stabilizing cervical surgery such as vertebral plating or distractable K-wire spacers[7] or vertebral titanium cage[8].

Prognosis depends on the severity of clinical signs and the degree of skeletal disease present, with mean survival times in both medically and surgically treated groups averaging 36 - 48 months before necessitating euthanasia[9][10]

References

  1. Canada West Vets
  2. da Costa RC et al (2006) Comparison of magnetic resonance imaging and myelography in 18 Doberman pinscher dogs with cervical spondylomyelopathy. Vet Radiol Ultrasound 47(6):523-531
  3. De Decker S et al (2011) Intraobserver, interobserver, and intermethod agreement for results of myelography, computed tomography-myelography, and low-field magnetic resonance imaging in dogs with disk-associated wobbler syndrome. J Am Vet Med Assoc 238(12):1601-1608
  4. Gutierrez-Quintana R & Penderis J (2012) MRI features of cervical articular process degenerative joint disease in Great Dane dogs with cervical spondylomyelopathy. Vet Radiol Ultrasound 53(3):304-311
  5. da Costa RC et al (2006) Correlation of motor evoked potentials with magnetic resonance imaging and neurologic findings in Doberman Pinschers with and without signs of cervical spondylomyelopathy. Am J Vet Res 67(9):1613-1620
  6. De Decker S et al (2009) Clinical evaluation of 51 dogs treated conservatively for disc-associated wobbler syndrome. J Small Anim Pract 50(3):136-142
  7. Shamir MH et al (2008) A method for intervertebral space distraction before stabilization combined with complete ventral slot for treatment of disc-associated wobbler syndrome in dogs. Vet Surg 37(2):186-192
  8. De Decker S et al (2011) Surgical treatment of disk-associated wobbler syndrome by a distractable vertebral titanium cage in seven dogs. Vet Surg 40(5):544-554
  9. da Costa RC et al (2008) Outcome of medical and surgical treatment in dogs with cervical spondylomyelopathy: 104 cases (1988-2004). J Am Vet Med Assoc 233(8):1284-1290
  10. da Costa RC & Parent JM (2007) One-year clinical and magnetic resonance imaging follow-up of Doberman Pinschers with cervical spondylomyelopathy treated medically or surgically. J Am Vet Med Assoc '231(2):243-250