Intervertebral disk disease is a vital and timely topic as we’re seeing more and more cases in the rehabilitation clinic and as well as in veterinary practices in general.
Description of Intervertebral Disc Disease
Intervertebral discs are pads of fibrocartilage located between most of the vertebra of the spinal column. These discs comprise an outer layer of tough, annulus fibrous tissue with nucleus pulposus, a gel-like substance, in the interior—rather like a jelly donut. Intervertebral discs act as shock absorbers to help protect the vertebrae.
Over time or as the result of certain activities, intervertebral discs may degenerate, start to bulge outward, and even rupture. If the discs rupture, the jelly-like nucleus pulposus substance inside escapes into the spinal column, pressing against the spinal cord or nerve roots. This pressure causes pain, nerve damage, and, sometimes, paralysis. This condition known as intervertebral disc disease or IVDD.
The Incidence of IVDD
IIVDD is the most common problem seen in veterinary neurology. Chondrodystrophic breeds are more affected, and the incidence in Dachshunds is particularly high, ranging from 17% to 22%. Chondrodystrophy refers to a disorder of cartilage formation. Recent studies from the United Kingdom show similar trends of increasing numbers of dogs seen in veterinary clinics that are suffering from IVDD.
Although it’s true that this disease is mostly seen in chondrodystrophic breeds, we need to make sure we look outside that box. We also see IVDD in sporting and working breeds.
Breeds at Risk for IVDD
The breeds most at risk for IVDD include:
- Basset Hound
- French Bulldog
- Cocker Spaniel
- Shih Tzu
- Cavalier King Charles Spaniel
- Llaso Apso
- German Shepherd (and other working breeds)
- Doberman Pinscher
Types of IVDD
There are two types of IVDD. The first type is typically seen in chondrodystrophic breeds and involves disc herniation. The second type is typically seen in nonchondrodystrophic breeds
Type I IVDD involves disc herniation and is characterized by these symptoms and signs:
- Cartilaginous deformity
- Tends to occur between three and six years of age
- High rate of recurrence. If the dog herniates in one disc space, it has a very high chance of herniating in additional disc spaces. I always tell owners that if one component of the body isn’t contributing to the dog’s ability to move, the body will compensate elsewhere. For example, T13 – L1 is a high mobility area. If that area is compromised, L1 – L2 will try to compensate, as will T12 – T13. Because of the increased movement in these areas, they’re become prone to problems, and this contributes to a high rate of recurrence.
- Acute or sudden onset. The dog just jumps off the couch and immediately starts having problems. Sometimes the onset is more subtle, and the problem takes 24 to 36 hours to manifest.
Type II IVDD is the disc herniation typically seen in non-chondrodystrophic breeds. It’s characterized by these symptoms and signs:
- Fibrous degeneration of the disc
- Generally slower onset of clinical signs and more progressive
- Higher incidence in sporting and working dogs
Imagining the indivertible disc space to be like a jelly donut, as we age, the nucleus pulposus portion of the disc goes from being a gel-like fluid that’s a great shock absorber to becoming crystallized and beginning to harden. At some point, the nucleus pulposus becomes so hard and inflexible that it ruptures the annulus fibrosis and moves into the spinal canal, where it places pressure on the spinal cord.
Although Type II IVDD is most commonly seen in nonchondrodystrophic breeds, this doesn’t mean that a dog of a chondrodystrophic breed is only vulnerable to Type I IVDD. They can also develop Type II IVDD, even though it’s more common for them to develop Type I due to their conformation. The same is true for nonchondrodystrophic breeds. Due to the types of activities that sporting and working dogs engage in, the development of Type II IVDD is more common, but they too can develop Type I IVDD.
The first thing we want to look at in a dog with IVDD is its level of mobilization.
Active motion determines what the dog is able to do and its pain level. Most of the time, the dog will avoid an activity if it causes pain. Our goal is to restore motion and function. The restoration of motion is a component of function, which, in turn, affects stability.
Stabilization is aimed at improving the strength of the core musculature—the abdominals and the large muscles of the spine.
We begin with standing exercises, balance exercises, and rhythmic stabilization.
For standing exercises, we start on a flat surface or the floor.
Initially, we work on having the dog stand for short periods of time only. In the photo above, we see Bailey, a 13-year-old Pug who’s had episodes of IVDD. He’s been treated pharmaceutically but never had surgery. His owners have no intention of pursuing surgery.
We started working with Bailey in our clinic initially three times a week, and now we see him twice a week. We began by having him do standing exercises on the floor. We instructed his owners on how to work with him as well.
We encouraged Bailey to stand for up to 10 seconds and, once he began to sink, we helped him get back up. If he was really tired, we’d allow him to rest. Our goal was getting him to stand solidly for up to 30 seconds. Once that goal was achieved, we moved him to an uneven surface (in the photo above, he’s on a wobble board). While Bailey was on the wobble board, we moved him from side to side to improve his stabilization by building his core muscles. This exercise is something that can be done every day, and the challenge level can be increased by using different surfaces.
There are many components involved in conservative treatment of IVDD. In the acute phase, the following modalities are used:
- Pharmaceutical therapy
- Laser Therapy
In the post-acute phase of IVDD, these modalities are used:
- Standing Exercises
- Balance Exercises
- Rhythmic Stabilization
- Postural Strength
- Underwater Treadmill
- Positional Traction
- Laser Therapy
- Alterations in Lifestyle
- Weight Loss
- Controlled Activity
Acute Phase Interventions
- Nonsteroidal drugs
- Pain management
- Muscle relaxants
- Stem cell therapy (currently in the research stages)
You, as the veterinarian, must decide what treatment modality seems to be the most potentially beneficial and reasonable when putting together a patient’s treatment regimen. Some combinations work better than others. You also need to communicate with the owner to discover what they’re able and willing to do for their pet. The treatment of IVDD is a very individualized process, and you and the owner need to collaborate on the best treatment protocol for your patient.
Sometimes, steroids are the best option to start with. Other times, it’s a combination of nonsteroidal drugs and pain management.
Stem cell therapy is showing promise in the treatment of IVDD, but this may not be available for many years. Regenerative medicine is an exciting new area in both the human and veterinary healthcare fields.
It’s important to consider laser therapy and start it as soon as possible in patients diagnosed with IVDD to reduce pain and inflammation, help tissue to heal, and enhance neural regeneration. The photobiomodulation aspect of laser therapy targets tissues and creates bioenergetic, bioelectric, thermal, and biochemical effects. The thermal effect causes an increase in nerve conduction and capillary dilation. The biochemical effect releases nitric oxide that helps with ATP production, fibroblast migration, macrophage activity, keratinocyte activity, RNA/DNA synthesis, and enzyme production. All of these effects contribute to a reduction in muscle spasms.
In many cases, laser therapy results in immediate pain relief. We also see an increase in circulation, improvement in flexibility, and a reduction in symptoms associated with osteoarthritis.
In the acute phase of IVDD, it’s optimal to laser the patient every day. Sometimes it isn’t possible for owners to bring their dogs to the clinic daily, so you need to schedule treatments as often as is reasonable for the owner to bring in their pet for treatment during the first 10 to 14 days following the IVDD injury.
You want to laser the affected or suspected region involved. If you’ve not made a definitive diagnosis of which disc space is affected by IVDD, laser the entire painful area. You want to laser the disc spaces above and below the confirmed or suspected IVDD space as well, to address any secondary and tertiary areas.
With an IVDD dog, I always ask myself why it developed a herniated disc. Was it because the animal was compensating for something else, because it’s overweight, or some other reason?
For example, in a dog that has lumbosacral disease—lumbosacral stenosis or lumbar IVDD—its iliopsoas muscles are often very restricted because they’re protecting the spine. I laser these areas to reduce inflammation, pain, and discomfort.
Laser therapy is an important part of the multi-modal approach to treating the patient.
Ice therapy is one of the best things for reducing inflammation and pain. I tell owners—especially those that have chondodystrophic dogs—that if they suspect a disc injury has happened very recently, put ice on it.
We want our patients with suspected IVDD to avoid activity until we know what’s going on. But how do we advise our clients about controlling their pet’s activity if it must be left alone? Many owners aren’t used to putting their pet in a crate. If the pet isn’t used to a crate, its symptoms may worsen, because it may jump or try to get out of the crate due to anxiety. Therefore, depending on the dog, crating can do more harm than good and might make the IVDD symptoms even worse.
A good solution for minimizing the pet’s activity is to use a baby gate or X-pen to confine it to a small area. The owners of one patient I work with that has disc issues used to leave him alone every Sunday when they went to church. They were gone for about an hour, and when they came home, they noticed the dog was worse. His back was in a hunched position. They set up a webcam to run while they were away and discovered he went crazy when they left the house. He’d frantically jump up against the windows, bounce on and off the couch, and so on. Now they give him a special treat before they leave and confine him to the kitchen. He still has freedom, but his anxiety is greatly reduced.
Typically, the treatment for acute cases is to restrict the patient’s activity as completely as possible for up to one month following the injury, only letting it outside for short, under-one-minute potty-break walks.
However, we know that complete inactivity isn’t good; it’s actually detrimental. So we want to permit controlled activity to help with the muscle activation and begin gentle stabilization.
In the “old days,” when a person injured their back, they were prescribed strict bed rest. That’s no longer the case in human medicine. In humans, there’s strong evidence that keeping active and returning to usual activities as soon as possible following injury or surgery is important for a good recovery. In contrast, prolonged bed rest is associated with higher levels of pain, greater disability, poorer recovery, and longer absence from work.
However, in the animal world, we still advocate restricted activity and rest. Of course, we’re dealing with two entirely different species. A human can understand when we explain which activities are safe to do and which are not, but a dog can’t.
We know that strict crate rest for weeks isn’t good. Controlling the patient’s activity is a necessity, so we recommend a cautious and gradual increase in exercise to assure that muscle and core strength isn’t compromised over the recovery period.