Intervertebral Disk Disease


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Intervertebral disk disease is a process that affects many Beagles. It is generally an age-related problem, occurring anywhere from three years and up.  In Beagles, it generally occurs in the neck vertebrae, but may also occur in the thoracic (chest) or lumbar (lower back) vertebrae. Intervertebral disks are cushions that lie between each vertebra and under the spinal cord. They allow the spine to flex, and they help to dissipate forces that are placed on the spinal column. They have two parts, a firm, rubbery outer portion and a soft, jelly-like inner portion. To help with understanding, you can visualize a disk to be similar to a vitamin E capsule.

The Beagle  is predisposed to IVDD because they are one of the chondrodystrophic breeds ( like Dachshunds, Pekinese, beagle, etc.). These breeds undergo an early type of disc degeneration (chondroid metaplasia) that leads to early mineralization of the discs. When the disease occurs, the disks begin to dehydrate.  This causes the outer portion to become brittle and the inner portion to become dried out and mineralized. The disks lose their flexibility and are not able to withstand the movement of the spine.   Because they can no longer flex with movement, they can begin to protrude out from between the vertebrae.  In more severe instances a disk can actually rupture, spilling out the inner portion.  Because the disk's outer covering is thinnest at the top of the disk, the protrusion or rupture usually occurs in that area. T he bad part is that the spinal cord is directly above the top of the disk, and it can be injured when the disks protrudes or ruptures. Symptoms begin to occur when the disk material presses upon the spinal cord.

The signs of this disease can range from mild pain to complete paralysis.  The signs can come on slowly or be very sudden.  Generally, the sudden cases are due to the disk rupturing and the material inside the disk impacting violently on the cord.  The more slowly progressing cases are generally due to a gradual increase in pressure on the cord from a protruding disk.  Dogs with mild, progressive signs will often yelp when you pick them up, seem reluctant to jump on the furniture or to go up and down stairs.

Diagnosis of this problem is usually made initially by the clinical signs. Steroid Responsive Meningitis should also be considered and rule out as the cause of symptoms.  Plain radiographs may sometimes be taken to rule out other possibilities, but generally, they are not helpful in diagnosing disk disease.  A special type of radiograph, called a myelogram is often very helpful. For a myelogram, your dog must be anesthetized to keep him completely still.  Then a special dye is injected into the spinal cord and radiographs are taken to see how the dye pattern appears.  Many veterinarians are now recommending MRI as the test of choice.  For an MRI  your pet must also be anesthetized. These tests are expensive and plus surgery costs can be in the $2000-3000 range.   You should discuss all options with your veterinarian and be prepare to make a decision for or against surgery if  you are going to go ahead with the myelogram or MRI. 

Signs of a disk problem range from being painful to being unable to move. The more spinal cord damage, the worse the clinical signs. Animals with the worse spinal cord damage from disk disease lose the ability to move and to feel (conscious sensation) their limbs. To know if an animal can consciously feel, the veterinarian will  have to pinch the toes and see if the animal vocalizes or tries to bite.  While this test may seem harsh, it is very important. If an animal has lost the ability to feel in the legs, its chance of walking again is about 50%. If an animal can still feel in the legs, even if they can't move, there is a 75% chance or greater that the animal can walk again if surgery is performed.

For milder cases of the disease, your veterinarian will often try strict crate rest and steroids for a period of two to three weeks.  The steroids reduce the inflammation to the spinal cord, and the rest allows the cord to heal and form some scar tissue between it and the disk material.  It is extremely important for you to keep your dog on strict crate rest with no jumping, no stairs and no extra activity at all.  Your dog must be walked on leash only and only for potty breaks.  If your dog is not crate-trained, speak to your veterinarian about sedatives to keep him/her calm.  Too much activity in this period could lead to an increase in the problem. (Please bear in mind that some cases will worsen no matter how quiet you keep your dog.)

For more severe cases or cases which progressively worsen, often surgery is the only option.  The surgical procedure is called a disk fenestration and simply put, the surgeon will go in and remove all the protruding or ruptured disk material, so that it can no longer affect the spinal cord.  At the same time, they often perform preventive surgery on the other disks in the affected area.  The surgery is not without significant risks. Your pet could be the same or worse after surgery, or your pet could die during surgery.  However, in most cases, your pet will show at least some improvement and many return to being completely normal. 

Long term care must be divided into two main sections, those dogs that have had surgery to correct the disease and those who did not.  Before discussing the two individual scenarios, there are a few things that apply to all the dogs.  First, all dogs with Intervertebral disk disease should always use a halter instead of a neck collar. If your dog is accustomed to them, a head collar, such as a Gentle Leader may be used.  However, great caution should be taken if your dog has never worn one, as some dogs do not react well to the initial use of this type of collar.  Another beneficial action is to raise your dog's feeding bowl so that it is level with his head; this will put less stress on the dog's spine and make him more comfortable.  Tug of war games, either between you and your dog or between two dogs, should also be avoided. You should limit jumping as much as possible.  Jumping places a lot of stress on the neck, especially jumping down.

For the dogs that have had surgery, after-care can often depend on how the dog responded to the surgery.  Although many dogs respond well to the surgery, some will have lingering after effects.  The dogs that have an excellent post-surgical recovery need little special treatment after the initial healing time.  It is suggested that dogs be given at least 3 to 6 months of recovery time before complete return to normal activities.  The body needs a long time to heal from this type of surgery, and during this process, the neck may be unstable; so it is important to take things very slowly, one day at a time.  It is important to have good communication with your veterinarian and a recheck should be performed before any major activities are commenced.  Dogs that may have lost sensation or function in their limbs may require physical therapy or motor-assistance such as a cart to help lift the rear end.  Physical therapy can involve many things, massage, swimming, controlled walking are all possibilities and you need to discuss what will work best for your dog with your veterinarian.

For dogs that have not had surgery, it is important to understand the disease can progress at any time, and care must be taken to protect the dog. You must learn to watch your dog closely for early signs that he may be in pain. 

Although basic care is outline, much of this must be determined based on you, your veterinarian, and most importantly, your dog and his condition.
Other good links on this condition are:
http://www.dachshund-dca.org/discbook.html

written by Ellen Parr

From the Columbia Willamette Beagle Club Newsletter   "The Beagler", and printed here with permission of the author.  Ellen is a Certified Veterinary Technician (graduated 1997),  experienced working in emergency and general practice hospitals, and has been in full time practice for three years . She shares her life with two Beagles, three Harriers, two cats, and a husband. Much of her experience on this particular subject unfortunately comes from direct experience, with both of her Beagles suffering from disk disease.  Pippi has been controlled without surgery, and Beau had to have surgery.

Edited by Ruth Darlene Stewart-Chairperson National Beagle Club -Health and Genetics Committee