In this first blog entry, we will address the number one underlying cause of spinal disease in dogs, which is intervertebral disc disease.  Just like in people, dogs have intervertebral discs that reside between their vertebral bones.  The bones of the vertebral column house or protect the spinal cord itself and the intervertebral discs act as cushions or shock absorbers.  In certain breeds these discs can undergo changes early in life and become prone to herniation.  These are chondrodystrophic breeds (long backs and short legs) such as Dachshunds, Pekingese, Lhasa Apso, Shih Tzu, Corgi, French Bulldogs, etc.  In other dogs, the discs can degenerate as a result of age.  Not all patients with disc disease require surgery.  It is important to have your pet evaluated and determine the best course of action for your pet.

Clinical signs we may see with acute intervertebral disc disease include back pain or arched back, neck pain or low head carriage, ataxia (wobbliness), weakness, dragging, scuffing, and even complete paralysis.  Depending on the area of the spine affected, urinary incontinence and even respiratory compromise.

The neurologic exam is used to determine the general location of the neurologic problem – we refer to this as “neurolocalization.”  Once this is established, advanced imaging (MRI) can be done to determine the specific site of disc herniation.  The MRI is also excellent at revealing the extent of compression, amount of disc material, epidural hemorrhage and/or intraparenchymal concussive injury (within the spinal cord).  It is important to remember that although the imaging gives us all of this important information, it is generally the neurologic exam that determines prognosis.  Most patients who still have nociception (pain sensation) will go on to recover function, however this can take weeks to months.  Occasionally, in severely affected patients, urinary incontinence can remain.  It is also important to note that a secondary cascade of inflammation is set off after the primary injury that can be difficult to predict and occurs at a microscopic level.

The post-operative care of a neurologic patient can be as minimal as crate restriction.  But it can often involve extensive nursing care such as turning patients every few hours, keeping them clean and dry and learning how to express their bladders.  It is important to discuss what the aftercare of your pet is going to entail before moving forward with advanced imaging and surgery.

Patients with intervertebral disc extrusions are thought to be at an increased risk for future herniations (up to 20%).  In French bulldogs this risk of recurrence can be as high as 50% within a year!  Other important things to know about French bulldogs:

• 45% of French bulldogs presenting for neurologic issues have intervertebral disc disease
• They tend to be younger age at presentation
• They have more severe signs at presentation
• They have a higher risk of epidural hemorrhage and lumbar discs
• About 20% (1 in 5) will have respiratory distress when presenting for disc extrusions
• They are known for their airway disease and gastrointestinal signs (regurgitation and hiatal hernias) which can predispose the breed to aspiration pneumonia

A compressive disc herniation will often require a hemilaminectomy surgery.  This surgery is done by an approach through the top portion of the back for thoracolumbar disc extrusions.  A window is drilled through the bones to remove the compressive disc material.