Intervertebral Disk Disease

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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. Recent genetic research has identified the gene variant that is responsible for this predisposition to IVDD. CDDY is the name of the test for this variant. Genetic testing has shown that over 99 % of all beagles at risk for IVDD due to this variant. This is proof of what has been accepted for many years, beagles are an at risk breed for IVDD.

Disc 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.

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 term 'Intervertebral Disc Disease' (IVDD) refers to several pathological processes involving the intervertebral discs. Click here for more detail explanation of types. 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.