3Intervertebral Disc Disease Small breed dogs with short, thick legs such as the Dachshund, Bassett Hound and Beagle are at the highest risk of IVDD.IVDD is a premature hardening of the center of the disc, and weakening of the outer layer of the disc.As the outer layer of the disc ruptures, the inner material is displaced upwards against the spinal cord. This herniated disc material injures the spinal cord and results in cord swelling and compression. Consequentially, the nerves within the spinal cord traveling to the legs and urinary bladder become damaged. This in turn results in loss of limb function that can range from weakness to paralysis, and loss of bladder control.Small animals with IVDD tend to have the degeneration of the discs begin to occur within the first few months of life, but the actual disc herniation typically occurs without warning at around 3 to 6 years of age versus other dogs (ages 8 to 10).
4Symptoms & behaviors of IVDD · Reluctance to move · Reduced activity · Slower movement · Stiffness or difficulty climbing stairs · Difficulty with walking and jumping · Very tense abdomen · Hunched back due to muscle tension · Crying or shaking · Inability to move rear legs (this is an emergency) · Loss of bladder and bowel control (this is an emergency)
5IVDD Treatment options Prognosis Early treatments for IVDD may be simple cage rest in which the dog is restricted from jumping. Treatment with corticosteroids, NSAIDS, muscle relaxers, and analgesics alleviate spinal cord pain, but can be dangerous because dogs that are pain-free tend to become more active (instead of rest) with the chance of additional intervertebral discs that can herniate and irreversibly compress the already damaged spinal cord. Surgical management of dogs with IVDD is often required to alleviate cord compression and resolve clinical signs. Surgery should be performed immediately if signs of paralysis are present. If a dog suffering paralysis from a compressed or slipped disc goes without surgery for more than 24 hours, the damage may become permanent.PrognosisWith all treatment options the healing of the disc is accomplished only through time. If a dog is allowed too much freedom too soon the disc will leak again and dog can be back where they started or worse.Over 80% of dogs will regain function, if they are operated before they loose sensation. Many dogs will be ambulatory within 2 to 4 weeks after surgery.The most common complication is recurrence of signs, usually due to extrusion of another disk.
6The spinal column is made up of four major vertebral regions: cervical (neck), thoracic (mid back), lumbar (low back) and sacral (pelvic).
7Because disc material and the spinal cord itself are not visible on plain X-Rays, further imagining is necessary to definitively diagnose the location of the disc rupture.In some cases, a dye is injected along the spinal cord (myelogram) to allow the DVM to see the compression of the spinal cord on the radiographs.Lateral view of the lumbar spineBeam Center: Over level of fourth lumbar vertebral body.Measurement: At level of first lumber vertebral body.
8X-ray of the ventrodorsal view of the thoracic spine Beam Center: Over level of caudal border of scapula (T-6)Measurement: At highest point of sternum
9X-ray of the ventrodorsal view of the cervical spine Beam Center: Over C4-5 intervertebral spaceMeasurement: C5-6 intervertebral space
10X-ray of the lateral view of the thoracic spine Beam Center: Over seventh thoracic vertebral bodyMeasurement: At level of seventh rib
11Intervertebral disks are located between the vertebral bodies starting at the second and third cervical vertebrae (C2-3) and extending to the seventh lumbar and first sacral vertebrae (L7-S1).The three sacral vertebrae are fused and therefore do not have disks.Intervertebral disks are present between the coccygeal vertebra as well, but are of little clinical significance.
13When a disk herniates into the spinal canal, the meningeal nerves become compressed and inflamed causing the animal a great deal of pain. In addition, the nerve roots themselves are often compressed, resulting in a great deal of pain for the affected animal and affecting the area that these nerves supply.
14Wobblers DiseaseWobblers disease is a condition of the cervical vertebrae that causes an unsteady (wobbly) gait and weakness in dogs.If left untreated, Wobblers disease may result in chronic pain and difficulty standing or moving.X-Ray image of a spinal cord compression in a dog (Rhodesian Ridgeback), caused by congenital malformation of os axis (arrows). 1:skull 2:humerusX-ray of the flexed lateral view of the cervical spineBeam Center: C3-4 intervertebral spaceMeasurement: Over level of C-7 (thoracic inlet)
15The term wobblers disease refers to a number of different conditions of the cervical (neck) spinal column that all cause similar symptoms.The causes of wobblers disease include: cervical intervertebral disk disease, abnormalities of the cervical vertebrae, and malformation of the cervical vertebrae due to poor nutrition.
16Commonly affected dog breeds Great DaneDobermanSt. BernardWeimaranerGerman Shepherd DogBoxerBasset HoundRhodesian RidgebackDalmatianSamoyedOld English SheepdogBull Mastiff
17Signs of Wobbler’s Syndrome Clinical signs vary widely depending on the amount of spinal cord compression caused by the cervical vertebral instability.Signs may have a rapid and sudden onset or they may progress slowly.The signs may or may not worsen.The dog may have neck pain, difficulty rising to a standing posture, wasting of the muscles (especially in the forelimbs), worn toenails, unsteady gait, and general difficulty in maintaining normal postures.
18Diagnosis Diagnosis is made through X-rays of the spinal column. Myelograms (injecting a contrast agent around the spinal cord) may be needed to evaluate the spinal cord.Additionally, an analysis of the cerebrospinal fluid may be performed.X-rays of the vertebra in the neck followed by a myelogram allow the DVM to see where and how many lesions exist there.
19Wobblers Disease In mild cases steroids and bed or cage rest may help. TreatmentIn mild cases steroids and bed or cage rest may help.In more severe cases, surgery for the dog with wobblers will need to be performed.In the most serious cases, no treatment may be possible.PrognosisThe prognosis for dogs with wobblers disease is variable.The earlier in the course of disease that surgery is performed, the better the outcome.Paralysis is always a possibility in dogs with wobblers disease and frequently these dogs cannot be helped.
21X-rays can be taken to view the areas of main compression in the neck. Generally three views of the neck are taken. All 3 views are from lateral position in which the dog is on its side while it is shot.One lateral is shot with the neck in its normal position, and the second view is of the neck flexed toward the toes of the dog, and the third is of the dog with its neck poised as if looking to the sky.
22X-ray of the lateral view of the cervical spine Beam Center: Intervertebral space of C-4 and C-5Measurement: Over level of C-7 (thoracic inlet)X-ray of the hyperextended lateral view of the cervical spineBeam Center: C3-4 intervertebral spaceMeasurement: Over level of T-1 (thoracic inlet)
23ReferencesRetrieved 11/28/09Bagley RS., Tucker RL. Specialty Board Review, Neuroradiology. Prog Vet Neuro 7:62, Retrieved 11/29/09Cauzinille L, Kornegay JN: Wobbler disease in a dog. J Am Vet Med Assoc 201:1225, Retrieved 11/29/09Retrieved 11/30/09Bagley, Rodney S. (2006). "Acute Spinal Disease" (PDF). Proceedings of the North American Veterinary Conference. Retrieved 11/30/09Jeffery N, McKee W (2001). "Surgery for disc-associated wobbler syndrome in the dog--an examination of the controversy". J Small Anim Pract 42 (12): 574–81 Retrieved 11/30/09Sumano H, Bermudez E, Obregon K (2000). "Treatment of wobbler syndrome in dogs with electroacupuncture". Dtsch Tierarztl Wochenschr 107 (6): 231–5. Retrieved 12/01/09
24Questions: What breeds of dogs are at highest risk for IVDD? What symptoms of IVDD are an emergency and requires immediate treatment by a DVM?With IVDD what is the percent of dogs that will regain function, if they are operated on before they loose sensation?What is a myelogram?Generally how many views of the neck are taken to diagnose wobblers disease?In what position are all the views taken?
25Answers:1. Small breed dogs with short, thick legs such as the Dachshund, Bassett Hound and Beagles are at the highest risk of IVDD2. Inability to move real legs. Loss of bladder and bowel control.3. 80%4. Injecting a contrast agent around the spinal cord5. 36. Lateral