Intervertebral Disc Disease By Roger Ross, DVM
This disease can happen to any breed of dog, but either for genetic reasons or because of the way their bodies are shaped, this disease is most common in dogs with short legs.
Dachshunds, beagles, bassetts, and shih tzus, for example.
The basics of the disease are fairly simple: there's a spongy disc
between each of our vertebral (back or spinal) bones that allow us to bend and flex without one vertebral bone rubbing against the other. But, if because of disease or degeneration, acute trauma, or constant trauma (from bad posture or body build, for example) the disc is squished or ruptures. This compresses the very sensitive spinal cord to some degree.
Degeneration of the disc is apparantly the most common reason for this disease. The inner part of the spongy disc is jello like in it's consistancy, and for some reason, even in young dogs, this jello like inner disc (called the nucleus pulposus) starts to dehydrate and loose it's spongy property. The disc becomes unhealthy, it no longer performs it's function which leads to stiffness and soreness of the back, and if it ruptures, the now firm jelly like stuff squishes up into the spinal cord causing anything from minor inflammation to paralysis.
Diagnostics:
1. Exam. We can often pinpoint the suspected disc rupture on palpation. But we can't be certain that we aren't missing another problem without x-rays. Perhaps the problem is actually just a "pinched nerve" or a "pulled muscle". Other causes of spinal pain and partial paralysis include inflammation of the spinal cord or spinal muscles from fatique, neuro-toxins, high fever, and fairly common; the tick borne diseases such as lyme disease and tick paralysis. Subcutainious cysts putting pressure down on the spine and kidney disease or colitis putting pressure up on the spine are possible ruleouts. If you (we vets) are too quick to come to a conclusion and don't check, you miss things. Our job is to be careful and meticulous for just this reason. Vets should be like airline pilots in this regard; careful and meticulous about checking before take off. I wish our politicians were more careful about spending our money on programs that sound good. As usual, I digress. Back to the subject.
2. Regular X-rays. For all the reasons indicated above, we recommend radiographs when we suspect disc disease. It rules a lot of things out, including spinal fractures, but you need to know that regular x- rays often miss disc disease even if that's the problem.
3. Myelograms. Myelograms are the best method for finding disc ruptures and are simply radiographs of the spine taken after we inject a dye into the space where the cord lies. This makes it much easier to see defects and disc ruptures. Your vet may or may not be comfortable with this delicate procedure, so may or may not refer you to a specialist.
4. Other ways to make a diagnoisis. I'm a little embrassed to admit, over and over again when I write these summaries and treatment outlines, that there's stuff out there I don't know much about. Hopefully you'll agree that I am presenting you with very helpful and accurate information about the basics, but don't be surprised to find that more up to date vets are using other techniques such as MRI's, CAT Scans, and such.
Treatment Options
Medical or Conservative Treatments
1. Rest, limited activity, and luck are sometimes enough for minor cases. If the protrusion is minor, the inflammation can go down with rest and time, the rupture scar over, and everything turn out okay except for a little less flexibility.
2. Medications for inflammation, pain , and to promote healing.
Please refer to the medications used in treating the symptoms of hip dysplasia in the article immediately above; they are the same.
Beware: Conservative medical treatment does often work, especially in less severe cases, but sometimes everything is going along pretty nicely, the dog is less and less painful, getting around better etc, but then jumps off the couch and lands a little hard and oomphf, the partially ruptured disc bursts open the rest of the way and the poor dog is paralyzed for life. Just so you know.
Surgical Repair (Laminectomy)
This is the treatment of choice for more severe cases, and ideally, should be done within a few days of the onset of paralysis.
The goals of surgery are to relieve the pressure off of the spinal cord and to remove the ruptured disc material from the spinal canal.
This involves the removal of the bony roof that lies over the spinal cord. This will help to remove the pressure off of the cord. This is a very delicate surgery done by specialists, after taking a myelogram, and with a little luck, will prevent your pet from being crippled or euthanized. It all depends on how much damage was done to the spinal cord. Usually if the dog is paralyzed from the disc rupture but still has sensation to his rear paws, there's a good chance that the surgery will be successful if done in the first 48 hours. After that the inflammation and necrosis of the cord may be too great for recovery.
Even when things go well, you need to expect a fair amount of time (several weeks to months) until your pet is walking normally again.
Post Op recovery can take a fair amount of effort. You often have to deal with "bed sores", constipation, inability to urinate normally, and so forth. You may have to keep your pet confined to prevent them from dragging themselves around dangerously. None of this is pleasant, but for a responsible adult, none of it's a big deal either; with a little nursing, gently physical thearpy, love, and time, your pet may return to near normal function. It can be quite rewarding.
Euthanasia
Disc disease can cause total paralysis and in such cases euthanasia may be the only merciful option. I'm going to chicken out of this discussion though...it's something you should discuss with your vet on a case by case situation.
Partial paralysis is no picnic either. And I wouldn't blame anyone for considering euthanasia for a pet unable to walk or suffering from secondary fecal and urinary incontinence. But before you automatically elect to put your pet down, know that some pets do remarkably well in those little carts made for paralyzed dogs and that I've seen quite a few dogs (and cats) recover with acupunture and chiropractory. If you can't afford surgery (or if too much time as elapsed for surgery to offer much success), consider a few inexpensive chiropractory visits and if that fails to help much, maybe look into acupuncture. If the cord isn't completely severed, there's always hope.
Another article about Disk Disease from the TEXTBOOK OF VETERINARY INTERNAL MEDICINE Client Information Series
by Richard A. LeCouteur
The spinal column is made up of a number of small bones called vertebrae that arc lined up like building blocks. A hole in the center of each vertebra forms a tunnel in which the spinal cord lies. The spinal cord is extremely important as it carries the messages from the brain to the rest of the body. The spinal cord is extremely delicate, and being surrounded by the bony vertebrae helps to protect it. Between each pair of vertebrae, just underneath the spinal cord, is a little cushion, called an intervertebral disk. Disks cushion the vertebrae from one another and provide flexibility to the spine during movement.
As a part of the normal aging process, these disks deterio-rate, resulting in so-called disk disease. Normally, each disk consists of an outer fibrous ring and an inner gelatinous center (a good analogy would be a jelly doughnut). With age this "doughnut" changes in its consistency: the outer fibrous ring becomes fragmented and the inner "jelly" center hardens to a consistency of hard cheese. The fragmented outer fibrous ring may no longer be able to hold this hard center in place, and movement of the vertebrae on either side may suddenly squeeze the disk out of its normal position. Unfortunately, this material usually moves upward and comes to rest against the spinal cord, bruising it in the process. This "slipping" of the disk often occurs explo-sively, causing significant damage to the spinal cord and pain to the animal. In this abnormal position the disk presses against the spinal cord, causing further damage.
This type of disk disease may occur in dogs and cats of any age or breed but occurs most commonly in the "short- legged" breeds (e.g., dachshund, French bulldog, Welsh corgi, Pekingese) and some other small breeds such as the poodle and cocker spaniel. It may also occur in larger breeds of dog, including Doberman pinschers.
The parts of the spine most commonly affected by "slipped" disks are the neck and the middle to lower back. When a disk "slips" out of place and pushes against the spinal cord, it usually causes the animal significant back pain and frequently the damage to the spinal cord interferes with the normal functions of the front and/or rear legs (depending on the location of the disk rupture). In addition to being in pain, the affected dog or cat may be lame, uncoordinated, and/or paralyzed.
These symptoms (pain, incoordination, and possibly paralysis) indicate that the dog or cat has a problem affecting the spinal cord but not the exact location or cause of the problem. Disk disease, a tumor of the spine, or an infection of the spine may all produce similar symptoms. Tests are needed to determine the exact location and cause of the problem and to decide on the appropriate therapy. In order to accomplish this, the patient must be anesthetized for x-rays and collec-tion of fluid from around the spinal cord. "Myelography" is an x-ray study in which a special dye is injected into the fluid surrounding the spinal cord. This then allows any disk material pushing against the cord to be identified on the x-rays. Analysis of the fluid around the spinal cord helps to rule out other causes of the problems such as infection.
In most cases disk disease is a problem requiring surgery to remove the disk material compressing the spinal cord. Occasionally, animals with disk disease are not treated by means of surgery. In these animals, strict cage confinement and immobilization are used. Usually this approach is used for a first bout of back pain in animals that do not have problems walking. Although strict cage confinement does not correct the spinal cord compression, it may temporarily reduce some of the pain and swelling around the spinal cord and permit the ruptured disk to "heal." As time goes on, it is not uncommon for animals treated without surgery to suffer repeated bouts of pain, lameness, and paralysis as additional disk material slips and compresses the spinal cord. With each bout of disk disease the spinal cord suffers additional permanent damage. Surgical removal of disk material from the spinal canal is the only treatment that provides rapid and maximal recovery of spinal cord function.
Cortisone administration to animals with disk disease is of therapeutic value only during the first 8 hours after the initial spinal cord injury. Current scientific evidence does not support the use of cortisone beyond this time. Further-more, the adverse effects of cortisone (e.g., stomach ulcers) must always be kept in mind.
The surgery used most frequently to remove disk material from around the spinal cord is called a laminectomy. For animals undergoing a laminectomy, the speed of recovery and the extent to which normal function of the legs is regained depend on many factors, including the degree of the damage to the spinal cord and the length of time that the spinal cord has been compressed by the disk material. Animals exhibiting severe neurologic signs (e.g., depressed feeling in their toes), a rapid onset of symptoms (hours), and a long period of time before surgery generally have a pro-longed recovery period and may have varying degrees of permanent damage.
More about Disk Disease
Roger Ross, DVM
Dr LeCouteur, in his artilce above, doesn't mention alternative treatments such as acupunture and chiropractry. Because many owners are not willing or able to afford the several thousand dollars expense of spinal surgery, I have been in the position many times of recommending a local chiropractor...instead of euthanasia. More than half have been cured! (about 8 out of 15 cases). I'm still skeptical, but hey.
I don't have any experience with acupunture cures for disk disease but some of my colleagues are enthusiastic
