Wobbler’s disease in dogs is known by many names: Wobblers Syndrome, Caudal Cervical Spondylomyelopathy, Cervical Vertebral Instability, and Spondylolitheses. No matter what it’s called, the effect is the same – the vertebrae in the lower neck of the dog put pressure on the spinal cord. This pressure comes from either malformation of the vertebrae or can be caused by trauma or a ruptured disk. As pressure increases the nerves in the spinal cord become damaged. Because nerves signals are not being transmitted properly, the animal is uncoordinated and ataxic, hence the name Wobbler’s.
Any breed of dog can develop Wobbler’s, but large and giant breeds seem to be at a greater risk than others. In some breeds, the disease appears to be genetically linked, such as in Great Danes, Doberman Pinschers, Borzois, and Basset Hounds. In Great Danes, Wobbler’s is normally seen in young dogs, however in other breeds the onset of Wobblers does not come until later in life.
Cervical (neck) lesions account for approximately one fifth of all intervertebral disc problems. Most patients experience neck pain as the first and most consistent clinical sign. Affected dogs hold their head and neck in a tense position, and are reluctant to elevate the head and neck when climbing stairs or to eat or drink. The neck often appears swollen or thickened, especially when muscle spasms occur. Dogs will whine, and will guard their neck, which is evident by periodic elevations of the ears and muscle spasms. Depending on the degree of damage and compression, the severity can range from being wobbly and ataxic (uncoordinated), to lameness, or even paralysis. If an intervertebral disc ruptures on one side only, it can result in lameness of one front leg. When discs rupture in the center of the spinal canal, both front and rear limbs become weak and this can progress to paralysis of all four limbs.
A thorough physical, orthopedic and neurologic examination must be performed by your veterinarian.
Radiographs of the spine are often performed to rule out fractures and luxation of the spine. Further diagnostic tests require general anesthesia and may include a myelogram, which is a contrast radiograph study in which a dye is injected around to spinal cord to highlight any compression. Frequently, a CT scan, which is a radiograph that allows viewing of individual sections of the spinal cord and surrounding tissues, can be used. Alternately or in addition to the CT, a magnetic resonance imaging (MRI) study may be performed.
The cause of Wobblers Syndrome is not known but it is thought that genetics and diets are major contributors to the disease. In some cases, the syndrome appears when large dogs grow very quickly as puppies due to excessive nutrition. In other cases there is no clear evidence as to what brought on the syndrome, which supports the genetic theory. Each case is different and varies in terms of disease progression, clinical signs, and severity.
In dogs with cases of Wobbler’s disease that are slow to progress and mild, treatment normally starts with medical management, consisting of corticosteroids to reduce inflammation and swelling. Combined with a lifestyle of very minimal activity, this can help keep symptoms from worsening. In more severe cases a neck brace may be required to help stabilize the neck. Surgery is also often performed. There a number of surgical techniques that can be performed, but all have the same the goal – to alleviate the compression on the cervical spinal cord and fuse the affected vertebrae. An incision is made to remove the ruptured disc material, and the degenerative center of the affected other discs is removed so they will not rupture. Surgery is considered to be more helpful in sudden onset (acute) cases as opposed to chronic, slowly progressing cases. Treatment will vary depending on severity of the compression, the clinical signs, and on the dog itself on a case-by-case basis.
The only way to prevent Wobbler’s disease is by ensuring that large and giant breed puppies are fed diets that promote slow, steady growth, rather than rapid growth.
Prognosis for dogs with Wobbler’s disease varies significantly with the degree of injury and the location of the injury. Most intervertebral disc ruptures that present in dogs that are still walking or have motor function have an excellent chance of recovering to normal or near normal function. Prognosis for return to good function is decreased, however, if motor function has been lost prior to the time of surgery. If deep pain perception is absent, recovery can be unlikely, especially if the duration of compression has been prolonged. Some dogs treated for intervertebral disc rupture will always have some degree of wobbliness while walking. Most of these dogs will require long term “life style” changes that include weight loss, the use of a harness rather than a collar, and prevention of traumatic activities like jumping or stair climbing. However, in some dogs surgery may be unsuccessful due to the inflammation associated with the surgery. Additionally, dogs with any form a disc disease are much more likely to rupture or damage other intervertebral discs.