By Dr. Becker
Intervertebral disc disease is a serious condition seen more often in dogs than cats.
Intervertebral discs are cushioning pads of fibrocartilage that sit between most of the vertebra of the spinal column. The discs have an outer layer of tough fibrous tissue and a center that is more of a gel-like substance. They act as shock absorbers for the bones called vertebra in the spinal column.
Unfortunately, intervertebral discs are subject to degeneration, bulging outward, and even bursting or rupturing. When something goes wrong with a disc, the material inside escapes into the spinal column, pressing against the spinal cord or nerve roots, which causes pain, nerve damage, and sometimes, paralysis. This is the condition known as intervertebral disc disease or IVDD.
Depending on the location of the damaged disc, problems can occur anywhere in the animal’s body from the neck to the rear limbs. In cats, the problem discs are more often found in the neck and upper back. In humans, the condition is sometimes called a slipped disc or a herniated disc.
IVDD is one of the most common neurologic disorders seen in pets, especially dogs. Most aging dogs have some degeneration of intervertebral discs, which commonly results in a condition known as spondylosis. Most of the time, spondylosis doesn’t cause pain or weakness and doesn’t progress to intervertebral disc disease.
Two Types of Intervertebral Disc Disease
There are two forms of IVDD in dogs -- Hansen Type I and Hansen Type II.
Hansen Type I is the acute, explosive herniation of a disc. This type of IVDD is typically seen in middle-aged chondrodystrophic dogs with breed-specific inherited skeletal deformities lurking in their DNA. These dogs include the Dachshund, Shih tzu, Beagle, Pekingese, Poodle, Corgi, Basset Hound, and others with characteristics of genetic dwarfism.
Hansen Type II IVDD involves a gradual progressive protrusion of disc material that affects non-chondrodystrophic breeds who are older, usually between the ages of 8 and 10. This form of IVDD is most commonly seen in German Shepherds, Labrador Retrievers, and Dobermans.
Obese and out-of-shape dogs of predisposed breeds are at much higher risk of acquiring IVDD.
The average age of kitties who develop the condition is 8 to 10 years.
Symptoms of IVDD
There are a number of symptoms that can occur with intervertebral disc disease, but they’re also seen with other conditions, which is why an accurate diagnosis is needed.
Signs you should watch for include reluctance to move the neck and head or a lowered head -- some animals only move their eyes to look at you. They don’t want to move their head or neck because it’s painful. An animal holding his head low and shifting just his eyes to look at you is definitely suspicious for IVDD.
Other symptoms can include back pain, stiffness, crying out unexpectedly when touched or while moving, abdominal tenderness or tenseness, an arched back or hunched posture, incomplete or inappropriate urination, dragging one or more legs, toeing or knuckling over when walking or standing, weakness, stiffness, an odd or tentative gait, reluctance to sit or stand, or an unwillingness to jump.
Some dogs have anxiety, because they know it’s going to hurt when they move.
Other signs: reduced appetite or activity level, loss of bowel or bladder control, trembling or shaking, a loss of general coordination, paralysis in one or more limbs, or, in a worst-case scenario, sudden collapse.
A complete neurologic exam should be performed to help identify the location of the injured disc. Regular X-rays may show a problem area in the spine, but the spinal cord and the actual discs don’t appear on X-rays, so special imaging may be required.
X-rays can be helpful in ruling out other potential causes of spinal cord damage, including tumors occurring in the bone, fractures, discospondylitis, and discospondylosis.
A myelogram, which requires general anesthesia, is a procedure in which a dye is injected into the spine, making it visible when X-rayed. A herniated disc or spinal cord compression can usually be visualized with this particular technique.
A spinal tap to assess cerebral spinal fluid is sometimes used to rule out other causes of symptoms such as infection, inflammation from autoimmune disease, or cancer.
The best method for visualizing the spinal cord – and if you’re planning to do surgery, certainly a necessary step – would be an MRI. An MRI is a non-invasive technique that produces the most useful images of the spine, spinal cord, nerve roots, and intervertebral discs.
The earlier IVDD is diagnosed and treated, the better your pet’s chances of avoiding a permanently painful and sometimes paralyzing condition.
Once a diagnosis of IVDD has been made and the affected discs located, a treatment plan can be developed. The goals for treating IVDD patients are to eliminate pressure on the spinal cord and resolve inflammation in order to return the pet to a pain-free and fully mobile life.
Treatment can involve medical management or surgical intervention, depending on the severity of the disease.
If the dog no longer has mobility and has lost deep pain sensation, the connection from the brain to the body has been severely compromised. Unfortunately, the only way to attempt to re-establish the connection is with surgery. Time is of the essence in these situations, and delaying surgery even for 24 hours can often dramatically reduce the possibility of a positive outcome.
If surgery is necessary, there are a variety of techniques that can be used. The goal of any procedure is to relieve pressure on the spinal cord at the site of the damaged disc.
In acute cases where the animal still has some mobility and a superficial pain response -- which indicates there’s still a viable connection between the brain and the body -- pain management and control of inflammation should be accomplished first.
In any case, once a pet’s pain and neurologic symptoms are well-controlled either medically or surgically, there will need to be an extensive period of complete rest in order for healing to occur.
All disc patients must have a well-padded bedding area -- a small area they can’t get up and move around in. If the animal can’t reposition herself on her own, it’s important to turn her every few hours to prevent bedsores.
Assistance with urination, defecation, eating, and drinking is often also necessary.
Importance of Physical Therapy for IVDD Patients
During this time of complete rest, there are some very important therapies that can speed healing and improve your pet’s chances of a successful outcome.
Acupuncture and electroacupuncture, which is sending a microcurrent of electricity to and from acupuncture points (which are really big nerve bundles), can be very beneficial at helping to re-establish the nerve connections in the body.
Massage with or without medical-grade therapeutic essential oils is very good for disc patients as well. Massage of limbs and axial muscles not directly involved with the site of the injury and passive range of motion exercises can help improve circulation and assist with lymphatic drainage.
Physical rehab technicians are trained to use gentle joint compressions to help maintain patient comfort and reduce pain. Also, these techniques help to maintain limb strength and muscle mass.
Laser therapy at the surgical site or over the area of injury will promote a more rapid healing response, and neuromuscular electrostimulation will help slow muscle atrophy from disuse.
When healing is far enough along, underwater treadmill therapy or swim therapy is an absolutely amazing tool for helping the body recover from neurologic trauma.
As patients continue to improve, a land treadmill enhances endurance and improves gait and movement patterning. Physio balls and specific therapeutic exercises can be utilized to improve limb strength and core stability. Cavaletti poles are very effective for improving proprioceptive input and coordination.
All that to say, pets who undergo rehabilitation after treatment for intervertebral disc disease heal faster, with a far better long term outcome than pets treated with medical or surgical intervention alone.
The good news is most pets who maintain deep pain sensation through an episode of this disease can be well managed without surgery, especially in cases where the condition is diagnosed and treated early.
Unfortunately, IVDD symptoms recur in about 50 percent of pets, especially if they are obese, out of shape, or if they’re allowed to jump freely. This is why regular physical therapy that focuses on establishing and maintaining core strength and muscle tone reduces the risk of recurrence, and helps keep disc patients’ quality of life excellent.