Intervertebral disk disease

There are two types of intervertebral disk disease. Type I (Hansen’s) intervertebral disk disease is an acute prolapsed of disk material into the spinal canal. It is most commonly seen in small breed dogs (Dachshunds, Toy Poodles, Beagles, Pekingese, Welsh Corgi, Lhasa Apso, Shih Tzu and Cocker Spaniels). Because of degeneration of the disk at an early age, we commonly see this disease in patients between 3 and 6 years of age. Type II IVDD is fibroid degeneration of the disk and is seen in older dogs, as it is slowly progressive. It is a disease that progresses at a slow rate and is typically seen in large breed dogs (German Shepherd, Labrador Retriever, and Doberman Pinschers). Signs are similar to degenerative myelopathy, neoplasia, and diskospondylitis.
Most of these injuries (Type I-IVDD) occur in the region of the spine where the ribs end (thoracolumbar region). This often results in loss of movement in the hindlimbs. Neck injuries (cervical region) are painful but do not typically result in neurologic (nerve) abnormalities. Injuries where the ribs begin (cervico-thoracic junction) and the hips begin (lumbo-sacral junction) have a decreased chance of improvement. If the forelimbs are affected by an injury further back in the spine, it indicates a severe injury and a worse prognosis for recovery. Pain occurs with all of these injuries due to the disk material compressing the spinal nerves.
It is always recommended to see a veterinarian or veterinary neurologist, if you think that an injury has occurred. Dogs can be treated surgically or non-surgically. Most dogs that are able to walk respond well to medical (non-surgical) management. Dogs that cannot walk have >=50% chance of regaining function and it will be an extended recovery period, if they do regain function. Dogs that recover from an acute episode have a 30% chance of recurrence. Medical management consists of strict confinement for 3-4 weeks, followed by a very slow return to exercise. They can also be given non-steroidal anti-inflammatory drugs and pain medication. Patients with neck injuries should wear harnesses (when walking) for the rest of their life to avoid any jerking motion to the neck. It is also important to be aware of whether or not these patients can express their bladder, or if part of their care requires bladder expression to avoid further complications. Surgery includes cutting through the vertebral bone and removing the disk material. Recovery after surgery may be intensive, requiring bladder expression physiotherapy and encouraging movement by towel walking. Improvement is expected within 1 week of surgery.Rehabilitation of these patients can be essential to recovery/return to use. As mentioned before, it is a very slow progression with medical management. It can take two weeks or more before these patients are ready for the simple act of weight bearing. Some of the methods used to increase strength and regain function in these patients include electrostimulation, cold/hot packs, passive and active exercise, massage, therapeutic ultrasound, laser, and underwater treadmill or swimming. Water has the advantage of decreasing the amount of weight the animal must carry during movement. Movement is encouraged much sooner in patients that have surgery.
Type II-IVDD can also be treated medically or surgically. Medical treatment is not curative and the symptoms will continue to progress, corticosteroids are typically used. Surgery can be used to prevent further degeneration, but because of the chronicity of the disease, we do not expect the animal to return to a pre-disease state. We use rehabilitation therapy in these patients to keep them moving and counteract the muscle loss that occurs during the course of the disease. Rehabilitation can enhance the quality of life in these patients as the disease progresses and maintain mobility for a longer period of time.
On May 7th, I will be doing a presentation at Berner University (Bernese Mountain Dog Club of America's National Specialty meeting). Part of my presentation will focus in on Degenerative Myelopathy, so expect this topic as my next blog! For more info on Berner University, visit www.berneru.org.
Thanks.
Jennifer Gearing, D.V.M.