What is Diskospondylitis?
The intervertebral discs are located between the bones of the spine (the vertebrae). Diskospondylitis is an infection of the intervertebral disc and the portions of the vertebrae adjacent to the infected intervertebral disc. Diskospondylitis causes painful damage / lysis to the vertebral bodies. It can lead to degeneration of the infected intervertebral disc, which can cause the intervertebral disc to herniate and put pressure on the spinal cord.
Diskospondylitis can also weaken the bones surrounding the intervertebral disc, which can sometimes cause the bone to fracture.
What Causes Diskospondylitis?
Diskospondylitis is most commonly spread from a distant infection in the body through the bloodstream and eventually to the intervertebral disc. The original infection can be from the urine, the skin, the teeth, the heart, and the reproductive organs (like the uterus and prostate). Diskospondylitis can also occur after a penetrating wound (like a bite wound) to the spine or after a spinal surgery.
Diskospondylitis is usually a bacterial infection, but a fungal infection can also occur. Certain types of bacteria tend to cause diskospondylitis more commonly than others, including Staphylococcus, Streptococcus, E. coli, and Brucella.
What Clinical Signs Occur with Diskospondylitis?
The most common signs of diskospondylitis are spinal pain and fever. Some animals will also develop neurologic abnormalities, like weakness and incoordination. Rarely, paralysis (inability to move the limbs) can occur.
Which Animals are Prone to Developing Diskospondylitis?
Any animal can develop diskospondylitis, but older dogs and medium and large breed dogs are the most commonly affected.
How is Diskospondylitis Diagnosed?
In some cases, radiographs of the spine can easily identify diskospondylitis. However, radiographic changes to the bones and the disc space may not be seen until the infection has been present for several (4-6) weeks. In those cases, an MRI of the spine can aid in early disease detection.
After diskospondylitis is identified on radiographs, CT scan, or MRI, the next step is to look for the source of the infection. To do this, sterile samples of urine and blood are taken and sent to a laboratory. At the laboratory, these samples will be placed on culture plates to help identify the type of bacteria present. The bacteria that grow are tested against several different antibiotics, and these results help your veterinarian choose the antibiotic that has the best chance to clear your pet’s infection.
If your dog has diskospondylitis, a blood sample is usually submitted to test for bacteria called Brucella, which causes an infection called Brucellosis. While Brucellosis is not very common in most areas of the United States, it is important to test your pet for this infection because it is an infection that can be spread from dogs to humans (zoonotic infection). It is important to test for Brucellosis to not only help choose the best treatment plan for your pet, but also to help protect you and your family.
If a fungal infection is suspected as the cause of diskospondylitis in your pet, then blood and urine samples may be submitted to test for various fungal infections.
How is Diskospondylitis Treated?
Diskospondylitis is usually treated with antibiotics. Antibiotic therapy is usually for many months, and the average length of treatment time in one study was 53.7 weeks. In most cases antibiotics are continued until there is no evidence of active infection on radiographs. If the antibiotics are stopped too soon, then the infection could return and may be more difficult to treat.
Most dogs with diskospondylitis are usually very painful, so multiple pain medications may be used initially to keep your dog comfortable. Usually once the antibiotic begins to control the infection, the level of pain dramatically decreases. Diskospondylitis causes the intervertebral disc and the adjacent bones to weaken, which makes dogs with diskospondylitis at an increased risk for a fracture, a luxation, or intervertebral disc rupture. Dogs with diskospondylitis need at least one month of very strict crate rest to help prevent a fracture or disc herniation.
What is the Prognosis for Diskospondylitis?
The prognosis for recovery from bacterial diskospondylitis is generally good, especially if your dog’s neurologic abnormalities are minimal. Dogs that are paralyzed from their infection, those that have an infection that is resistant to most antibiotics, and those with a fungal infection may have a more difficult time making a full recovery. Dogs who recover fully from diskospondylitis have some risk for a future recurrence of the infection.
References
- Dewey CW. Disorders of the Cauda Equine. A Practical Guide to Canine and Feline Neurology, 2008: 399-401.
- Platt S, Garosi L. Spinal Pain. Small Animal Neurological Emergencies, 2012: 226.
- Burkert BA, Kerwin SC, Hosgood GL. Signalment and clinical features of diskospondylitis in dogs: 513 cases (1980-2001). JAVMA 2005, 227(2):268-75.
- Harris JM, Chen AV, Tucker RL. Clinical features and magnetic resonance imaging characteristics of diskospondylitis in dogs: 23 cases (1997-2010). JAVMA 2013, 242(3):359-65.