The spinal anatomy of dogs is not all that different from humans. Dogs have a spinal cord allowing for communication between the legs and brain, which is encased and protected by a spinal column made up of vertebral bones (cervical, thoracic, and lumbar) (Figure 1). Except for the very first two cervical bones, each vertebral bone is separated by a shock-absorbing intervertebral disc (IVD). At the juncture of each vertebral bone, just above the IVD, a small nerve root leaves the spinal cord and spinal column to extend into the body where it exerts it’s affect (Figure 2).

The main differences between dogs and humans are the mechanics of the spine since dogs are quadrupeds, and the genetic predisposition of certain canine breeds to be affected by IVD disease, (or IVDD). Dogs, (and for that matter cats), stress their spines a great deal everyday with routine activities. Each time a dog jumps up on the bed, jumps for the ball, or jumps into the back of the SUV, the spine is flexed and then acutely extended, putting increased forces at the low cervical, mid-thoracic, and especially lower lumbar spine. These recurring stresses can result in chronic fatigue and microscopic damage to the IVD. The other major difference between dogs and humans is the genetic predisposition to IVDD. The process is termed chondrodystrophy and is manifested classically in Dachshunds.

Disc herniations can be acute or chronic and result in an entire spectrum of clinical signs from pain only to complete paralysis. Chronic disc herniations result in gradual on-set of signs (Figure 2). The most common locations of chronic disc herniations are low cervical, mid-back (e.g., thoracolumbar, or T-L), and lower lumbar or lumbosacral regions.

Dog breeds affected by chronic IVDD include: German Shepherds, Labradors, Golden Retrievers, Rottweilers, and Northern breeds. That being said, just about any dog can be affected by a chronic disc herniation. Usually chronic disc herniations cause pain but not paralysis.

Rapid, acute disc herniations occur most commonly in Dachshunds although other breeds include Cocker Spaniels, Basset Hounds, Corgis, some of the terrier breeds, and mixes thereof are also often affected (Figure 3). In these breeds, IVDs degenerate at a very early age, (even less than a year) and frequently results in more acute and severe disc herniations sometimes even resulting in paralysis.

Ultimately, the key to success in dogs with some form of disc disease is to have them evaluated by a veterinarian surgeon sooner than later. As mentioned above, disc herniation can result in various signs from pain to staggering to paralysis. Acute onset of paralysis or severe staggering is an emergency and these patients may require surgery as soon as possible. Even in the more chronic cases with pain only, early evaluation is key to ensuring the well-being of your pet.

Management of disc disease can be medical or surgical or both. In patients with pain only, medical management including CAGE REST, CAGE REST, CAGE REST plus or minus glucocorticoids (steroids) and analgesics is usually recommended. Patients with recurrent painful episodes may also benefit from surgery. In dogs with paralysis, surgery is unquestionably the treatment of choice.