Intervertebral discs are the discs that sit between vertebrae of the spine. They act as a shock absorber and cushion between the spine segments. They are made of an outer layer and a gelatinous inner material. The inner disc material can degenerate over time and become fibrotic and hard. This degeneration can lead to disc protrusions or hernations. There are two types of disc herniations.
In a Type 1 disc herniation, the fibrotic inner material cannot withstand normal forces and breaks through the outer layer of the disc and goes into the spinal canal, compressing the spinal cord. This is the most common type of disc disease in Dachshunds or other breeds with long backs. The herniation usually occurs quickly and can cause symptoms ranging from just pain to full paralysis of the back legs.
In a Type 2 disc herniation, the degenerated material pushes out on the outer layer causing it to bulge into the spinal canal, compressing the spinal cord. This type of disc disease is more common in medium to large breeds. The onset is usually gradual and may be associated with arthritis of the spine.
When a disc protrusion or herniation is causing compression of the spinal cord, the first spinal area that is usually damaged is the part in charge of proprioception (the ability to determine where a limb or joint is in space). Therefore, the result is loss of balance or holding the limbs in unusual positions. Further into the spinal cord is the sensation of superficial pain. That is the second area that can get damaged. Lastly is the sensation of deep pain which is closer to the center of the spinal cord.
Signs of IVDD include weakness in the hind limbs, loss of balance, placing the limbs in abnormal positions, standing on the top of the paw, paralysis, loss of bowel and bladder control, and back pain. Back pain can present as holding the head low, hunching the back, not wanting to walk or move, or avoidance of normal behaviors.
A thorough neurological exam can help narrow in on the area of the spinal cord that is being affected. Though radiographs can reveal signs suggestive of IVDD, determining the type and extent of damage is best accomplished through an MRI, which requires anesthesia.
The extent and type of injury will dictate recommended treatments moving forward. Surgery may be recommended if there is severe pain or complete paralysis of the limbs. Conservative management may be better if the symptoms are less severe. Anti-inflammatory medication is usually recommended. Whether an animal has surgery or not, rehabilitation can be beneficial for improving function and comfort.
In rehab, the first thing we focus on is decreasing pain and swelling around the site of injury. We utilize electrotherapy, laser therapy, ultrasound therapy, and pain medications to get pain under control. We then focus on relaxing the muscles surrounding the spine. Rehab techniques are then focused on bringing back sensation and proprioception. Once proprioception is improved we work on stability. We start with positional balance exercises and then progress into dynamic movements. We focus on retraining transitions and taking appropriate steps. Fine tuning those movements are very important. Lastly we focus on rebuilding the stabilizers to the spine to prevent future injuries. We can also help make recommendations for assistive devices for your pet, such as booties or carts based on their needs.
We are heavily focused on teaching you how to take care of your paralyzed pet at home. We educate on how to properly lift, how to assist your pet through transitions, how to properly support through walking, and how to care for urination and defecation properly. We create a home exercise program directed towards getting your pet functional again. We work very closely with you to make sure the care for your pet is easier at home and more beneficial to their recovery.
Lorenz, M. D., Kornegay, J. N., &; Oliver, J. E. (2011). Handbook of veterinary neurology (5th ed.). St-Louis, MO: W.B. Saunders.
DeLahunta, A., Glass, E., &; Kent, M. (2015). Veterinary neuroanatomy and clinical neurology (4th ed.). St. Louis, MO: Saunders Elsevier.
Evans, H. E., Christensen, G. C., &; Miller, M. E. (1979). Miller’s anatomy of the dog. Philadelphia: Saunders.