Intervertebral disk disease (IVDD) is a painful, debilitating spinal cord disease. Sadly, humane euthanasia of an affected dog is sometimes considered. Long-backed, short-legged dogs are thought to be at the greatest risk of developing IVDD, but any dog can develop the disease.
The two categories of IVDD are:
Hansen Type I: This involves traumatic rupture (herniation) of the intervertebral disk. If the disk material is ejected upward, it will cause pain to the dorsal longitudinal ligament and could compress the spinal cord, resulting in nerve dysfunction. If the disk material is ejected sideways, it could affect the roots of the spinal nerves, causing pain and nerve dysfunction. Approximately 25% of Dachshunds experience Type I disease at some point in their lifetime.
Hansen Type II: This is a slower degenerative disease in which the annulus fibrosis wears away, causing the intervertebral disk to slowly impinge on the dorsal longitudinal ligament, the spinal cord, or the roots of spinal nerves over a period of months to years. Type II disease is mostly seen in German Shepherd Dogs.
IVDD in Dogs Stages
Clinical signs of IVDD vary with the disease’s progress. The earliest stage of IVDD is localized pain. With increasing severity of the disease, signs may include:
- Poor proprioception, which is the dog’s ability to recognize where the limbs are in space
- Inability to use one or more limbs
- Impairment of the muscles that control urinary and fecal continence
- Decreasing ability to detect superficial pain that may increase to deep pain
Diagnosing IVDD in Dogs
A diagnostic workup of suspected IVDD starts with a neurologic exam and evaluation for pain. Other problems with similar symptoms, such as vertebral fracture or dislocation, a tumor affecting the spinal canal or the nearby spinal nerves, or a fibrocartilaginous embolism (FCE), will be ruled out to make the diagnosis of IVDD.
Proprioception: Conscious proprioception reflexes are tested by flipping the paws of a standing dog upside down so that the top of the paw is on the floor. A normal dog will flip the paw right back into normal orientation with the pads of the paws facing the floor. General proprioception can be tested by leaning the dog to the side with support, to see if the paw automatically adjusts position to prevent a potential fall.
Gait: The dog’s gait will be evaluated. Dogs with proprioceptive defects may audibly or visibly scuff their feet as they walk, and the claws on the affected paws may be much shorter than on unaffected limbs because of the scuffing. Dogs may be ataxic (uncoordinated gait), sometimes in just the rear limbs (giving a clue to location of disk herniation).
Anus: The anus is examined for muscular tone and incontinence.
Ability to feel pain: In dogs who are unable to use their limbs, a strong pinch is applied between the toes of the affected limb. If the dog doesn’t withdraw their paw from the noxious stimulus, they are considered to lack deep pain.
Testing: X-rays may help determine if there is a fracture or dislocation causing the clinical signs. Sometimes mineralized disk material can be visualized, and sometimes there is a narrowing of the intervertebral space, giving clues as to where disk herniation may have occurred.
More sophisticated diagnostic tests may include myelography, CT scan, or MRI, which can help localize the precise location of spinal cord compression.
Treatment for IVDD in Dogs
An important treatment of IVDD is exercise restriction. Restriction to a crate is best, with trips outside on a short leash, only to toilet.
If the dog’s symptoms are relatively mild, medical treatment with steroids or a non-steroidal anti-inflammatory drug (NSAID) could be considered, along with muscle relaxants and other pain medication. Treatment with cold therapeutic laser can relieve discomfort. Mild oral sedatives can help keep a normally active dog quieter and less anxious.
If the clinical signs are severe (paralysis, incontinence), surgery might be an option, with the goal of relieving the compression of the spinal cord. Surgery is not a guarantee of a return to function, and usually there is a long course of physical rehabilitation therapy needed to help the dog walk again. The therapy can include in-office exercises and manipulations, underwater treadmill therapy, and a home exercise program.
IVDD: Home Care
If the dog recovers from a bout of IVDD, it is recommended to consider removing activities that involve jumping and quick turning from the dog’s lifestyle. This includes things like fetch, agility training, and off-leash hiking.
If surgery is not opted for, or if surgery was unsuccessful in returning function, options include using a cart to help the dog regain some mobility and beginning home nursing care, where the owner learns to do the expression of the urinary bladder and manage fecal incontinence. Home nursing care for a paralyzed dog requires a great deal of commitment in time and energy, however, and if the owner cannot commit to that level of care, humane euthanasia may be considered.
