Discospondylitis is an infection of the intervertebral disk and adjacent vertebra and may be associated with significant illness and neurologic impairment if definitive diagnosis and initiation of appropriate antimicrobial treatment are delayed.
The infection typically spreads to the intervertebral disk via the bloodstream from another source of infection such as the bladder, reproductive organs, abscesses, open wounds, respiratory tract and oral cavity. Migrating foreign bodies and penetrating wounds can also be a source of infection. Bacterial infections, especially staph infections, are more common and typically easier to treat than fungal infections.
Clinical signs in affected animals are often nonspecific and highly variable and can include lethargy, anorexia, weight loss, fever and spinal pain. Affected dogs may be neurologically normal or they may have varying degrees of neurologic impairment spanning from spinal pain only to paralysis. Neurologic deficits in this disease can be the result of extrusion of intervertebral disk material, scar tissue formation within the vertebral canal, fracture or dislocation of the vertebral column, or meningitis/myelitis.
Any age dog can be affected, although it is generally accepted that the risk increases with age. Typically males are more often affected than females, and large breed dogs including the Great Dane, Boxer, Rottweiler, German Shepherd and Doberman Pinscher appear to be at a higher risk.
Discospondylitis can occur in any area of the vertebral column, and many sites can be affected simultaneously. Conventionally, the diagnosis of discospondylitis has relied on plain radiographic findings; however MRI is a more sensitive imaging modality and may be necessary to detect early cases of discospondylitis or to better determine the cause for severe neurologic deficits, if present.
Urine and blood cultures provide the best chance of identifying the causative organism, but in some cases, needle aspiration of the affected intervertebral disk or surgical biopsy may be necessary. Treatment typically entails long-term treatment (months) with an appropriate antibiotic or antifungal medication, analgesics and anti-inflammatories. In severe cases, surgery may be necessary to decompress the spinal cord and/or stabilize the spine. The prognosis overall is variable, and is generally better for those dogs in which the disease is diagnosed early, and appropriate and aggressive treatment is instituted.