Dr. Arnold Plotnick
X-rays. Diagnosis is usually made based on X-ray findings. Development of X-ray abnormalities, however, may take 2 to 4 weeks after infection. Therefore, early on in the disease, X-ray abnormalities may not be seen.
Myelography. This technique involves injecting a dye into the space surrounding the spinal cord, so that the spinal cord can be examined. It is performed in patients with substantial neurologic abnormalities, usually as a prelude to surgery. This procedure is usually performed at universities or referral centers.
Computed tomography (CT scan). CT scans are excellent for detecting subtle irregularities at the edges of the infected vertebrae, compared to X-rays, and often detects early infections that would be missed on X-rays. The procedure is expensive and is only performed at universities and referral centers.
Magnetic Resonance Imagine (MRI). This is the preferred method of diagnosing diskospondylitis in humans, allowing evaluation of large areas of the spine on a single set of images. It also identifies infected tissue earlier than X-rays can. This procedure is performed at universities and referral centers.
Radionuclide Bone Imaging. This is another specialized technique for identifying infection of the discs and the adjacent vertebrae. Infected tissues show a positive radioactive scan, while healed tissues show a negative scan. This fact makes this technique a useful way to monitor if treatment has been successful. This procedure is only available at a few universities.
Laboratory tests. Blood tests alone are not enough to make a diagnosis of diskospondylitis, however, they help support a diagnosis. White blood cell counts may be normal or they may be increased. Urinalysis may show evidence of a urinary tract infection. Blood cultures are positive in 45 to 75 percent of diskospondylitis cases, allowing identification of the responsible organism. Urine cultures identify the offending organism in 25 percent of cases. A bacterium called Brucella is occasionally responsible for causing diskospondylitis, and a blood test looking for antibodies to this bacterium should be performed; it is usually positive in approximately 10 percent of cases.
Needle aspiration and biopsy. Insertion of a needle into the space where the disc resides and is a safe procedure for obtaining a sample of material for culture and microscopic analysis. The procedure requires general anesthesia, and is performed only if the patient does not respond to initial antibiotic therapy, in cases of suspected cancer, or when the diagnosis is otherwise unclear. This procedure is usually performed at universities or referral centers.
The initial treatment of diskospondylitis usually consists of antibiotics, cage rest and pain medication. Clinical signs such as spinal pain and fever usually resolve within five days of starting effective therapy, although neurologic problems, if present, resolve more slowly. If medical therapy is unsuccessful, surgery may be necessary.
Antibiotics. Antibiotics are the mainstay of therapy. Antibiotic selection is based on the results of blood cultures, urine cultures, and the Brucella test. While waiting for these results, an antibiotic that is effective against the organism most commonly responsible for diskospondylitis (Staphylococcus) is chosen. Therapy for the first three to five days is usually intravenous. After that, oral antibiotics are usually administered.
Cage rest. In addition to antibiotics, the patient's activity should be restricted to minimize discomfort and the chance of fracturing or luxating (dislocating) the spine.
Analgesics. Non-steroidal anti-inflammatory drugs may be needed to control pain in some cases, but should be used very carefully, as they may cause the clinical signs to temporarily go away despite the fact that the infection may be progressing. If analgesics are used, they should be discontinued after three to five days to assess the effectiveness of the antibiotic treatment.
Surgery. If initial therapy is unsuccessful, a surgical biopsy may be necessary to confirm the diagnosis. Patients with severe neurologic deficits may need surgery to relieve pressure on the spinal cord that can occur if an infected disc ruptures, or if a spinal fracture or dislocation is compressing the spinal cord.
Optimal treatment for your pet requires a combination of home and professional veterinary care. Follow-up can be critical, especially if your pet does not rapidly improve. Administer all prescribed medications as directed. Alert your veterinarian if you are experiencing problems treating your pet.