Clean Run - June 2011 - 51

Intervertebral Disc Disease in the Canine Athlete
By Peter J. Lotsikas DVM Diplomate ACVS, Chris Leasure DVM, Faith M. Lotsikas DVM, CCRT, photos by author

Two weeks ago, a former colleague brought her eight-year-old robust yellow Labrador to VOSM for evaluation of acute neck pain of seven days duration. Seamus is an active Lab, but this particular incident was not associated with known trauma. He had been started on an oral corticosteroid and muscle relaxant, with little to no improvement. Upon examination, he could barely lift his head without vocalizing in pain. An MRI revealed a disc rupture between his fourth and fifth cervical vertebra. The following day, Seamus underwent surgery to alleviate the spinal cord compression in his neck. A large amount of disc material was removed from the vertebral canal, and Seamus was a new dog a mere 24 hours after surgery. Unfortunately, this is a scenario that presents all too often at our hospital. Let’s take a closer look so you can become more familiar with this condition. Anatomy
The normal canine spine is comprised of seven cervical, thirteen thoracic, seven lumbar, three sacral, and a varying number of coccygeal (tail) vertebrae that house and protect the spinal cord. Intervertebral discs exist between all adjacent vertebrae, with the exception of the first two cervical vertebrae and the sacral vertebrae. These discs provide stability and flexibility to the vertebral column, and act as shock absorbers for the spine. Each disc is like a jelly donut, composed of an outer shell (annulus fibrosus) and a central jelly-like portion (nucleous pulposus). The fluid nature of the inner disc allows it to absorb shock. The capacity to absorb shock is diminished with the loss of the normal composition of the gelatinous center. higher risk for developing this condition as compared to dogs that participate in other sports due to the repetitive flexion and extension of the spine over various pieces of equipment.

Types of Disc Disease
Intervertebral disc degeneration occurs with aging and may precede disc herniation. There are two main types of disc degeneration in dogs: 1) chondroid metaplasia and 2) fibroid metaplasia. Chondroid Metaplasia (Hansen Type I IVDD) This type of degeneration occurs mostly in chondrodystrophoid breeds (those that have genetic mutations that affect the development of cartilage like the Dachshund, Pekingese, Shih Tzu, and so on) with the changes starting during the first two years of life. A peak clinical incidence
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Predisposing Factors
Intervertebral disc disease (IVDD) can affect any size or breed of dog. Commonly affected small breed dogs include the Dachshund, Poodle, Pekingese, Cocker Spaniel, Shih Tzu, Lhasa Apso, and Beagle. Basset Hounds, German Shepherds, Labrador Retrievers, and Doberman Pinschers are the most commonly affected large breed dogs. Dogs that participate in agility are at
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Clean Run - June 2011

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