Canine Cervical Disc Disease

Winston is a dog owned by Sarah W. They both recently moved from California. Winston is a very polite handsome five year old male Jack Russell mix breed weighing about 11 pounds. His main problem was he had occasional pain from time to time in some non specific area without any apparent cause. Since he was adopted just a few years ago, Sarah didn’t really know just how long this pain has been a problem. Winston knew but he wasn’t saying. Recently, Winston’s pain got so bad, he wouldn’t let a groomer touch his body. When an owner describes sudden “yelping”, with no apparent trauma or cause, I start thinking of cervical disc disease. Of course it could have been many other diseases, but after a routine and neurologic (nervous system) examination, I decided to take radiographs of the cervical vertebrae (the neck). The exam revealed that Winston’s head and neck appeared to be tense and stiff, and he tried to avoid lifting his head when I push the head up toward the ceiling. The radiographs confirmed the tentative diagnosis of cervical disc disease.

 Winston’s x-ray showed calcification between two vertebrae and a narrow intervertebral space. Cervical (neck) lesions account for approximately one fifth of all intervertebral disc problems. Most patients experience neck pain as the first and most consistent clinical sign. “Yelping” or screaming often accompanies this pain. This occurs when there is a moderate disc rupture. The head and neck are held in a tense position with the patient reluctant to elevate the head and neck. Intervertebral disc disease is the most common neurologic syndrome seen in dogs. Disc degeneration has been reported in 84 breeds with particular susceptibility in certain small breeds. These breeds (Dachshund, Pekinese, Poodle, Beagle, etc.) have characteristic skeletal changes that predispose the discs to degenerate at a very early age. Intervertebral discs act as cushions between the vertebrae and function as the shock absorbers of the spine. A normal disc has two regions: a resilient gelatinous nucleus (center) and an outer fibrous ring that encircles the nucleus (see Fig.1). A degenerative disc loses its resiliency when its jelly-like center calcifies and develops a gritty, hardened consistency. No longer able to cushion the vertebrae, the center is predisposed to bulging and to rupture (see Fig. 1), resulting in pressure on the spinal cord, pain, and sometimes paralysis. Figure 1 Diagnosis A diagnosis of intervertebral disc disease is made based on the history and neurologic examination. Radiographs (x-rays) can reveal the presence of degenerative, calcified discs and may outline narrowed disc spaces with evidence of rupture and calcified disc material in the spinal cord. A definitive diagnosis may require a myelogram (a contrast dye study of the spine) to confirm and document not only the location of the ruptured disc but also the amount of spinal cord swelling. The myelogram is a common and safe diagnostic procedure when performed with care and under proper conditions. Because cervical discs by nature rupture slowly, the symptoms may come and go for some time. Early or mild cases are often treated medically. These medical treatments, which often include corticosteroids to relieve the cord swelling and pain caused by intense inflammation, become unrewarding as more disc material pushes against the spinal cord. The treatment of choice to reverse the symptoms and return the patient to a normal pain free life is surgical removal of the ruptured portion of the disc from its compressive position under the spinal cord. Treatment After radiographs and possibly a myelogram confirm the involved intervertebral site, a surgical decompression technique (a ventral cervical slotting procedure) is performed from an incision under the neck to remove all of the ruptured disc material. The architecture of the disc space is maintained to allow for a normal recovery. This is exactly what we performed on Winston. Sarah W with Winston – “going home”. The remaining discs in the area undergo fenestration, a procedure which involves removal of the degenerative center of the other discs in the neck. This procedure includes up to five intervertebral discs and involves cutting a window in the outer fibrous rim of the discs followed by extraction of the calcified, degenerative centers. This prevents recurrence of any disc rupture, while allowing normal motion and pain free movement following surgery. As the resected center of the disc scars, there is little or no effect on mobility. Winston was operated on for cervical disc disease using the ventral cervical slotting procedure. The following day he allowed our groomer, Donna to handle him. He was groomed without any pain or objection.  That made Sarah very happy and Winston had an uneventful, painless recovery. The Providence Veterinary Hospital Blog is a publication of Peter Herman, VMD, at the Providence Veterinary Hospital, 2400 Providence Ave. in Chester, PA. Contact Dr. Herman at 610-872-4000 or visit us at http://www.providencevet.com