What is IVDD?
In between the bones of the spine are a gelatinous substance that is surrounded by a thicker outer layer. This area is known as the intervertebral disc and is used as a shock absorber for the spine. When the disc herniates, it can cause two different types of damage to the spinal cord, concussion or compression. There are two types of IVDD, known as Hansen Type I and Hansen Type II.
Hansen Type I is commonly seen in chondrodystrophic breeds (dachshunds, corgis, beagles, etc.) and involves an acute rupture of the disc. While the disc becomes damaged from calcifying over time, the rupture generally occurs as a result of forceful impact (jumping, landing, etc.). After the disc(s) have ruptured, the material can cause compression of the spinal cord and result in pain, difficulty walking, paralysis, and the inability to urinate.
Hansen Type II is commonly seen in large breed dogs, such as the Labrador retriever, German shepherd, and the Doberman. With Type II, the discs generate and become hardened over a longer period of time, but can eventually also bulge or rupture and cause spinal cord compression.
While a disc can bulge or herniate anywhere along the spinal column, 65% of accounted disc ruptures occur in the thoracolumbar (midback) area, while 18% occur in the cervical (neck) region.
What are the Symptoms of IVDD?
The common symptoms of IVDD are:
- Pain in the neck or back region
- Unwilling or unable to walk
- Difficulty urinating and defecating
- Shaking or trembling (sign of pet being in pain)
- Knuckling on paws
Diagnosis of IVDD
To make the diagnosis of IVDD, your veterinarian will begin with a physical exam to check your pet’s orthopedic and neurologic status. Once the degree of severity is confirmed, your pet will either begin conservative treatment or begin a series of diagnostic imaging before surgical intervention.
Owners should be aware that these breeds of dog are predisposed to IVDD:
- Dachshund (45-70% of IVDD cases)
- Shih Tzu
- French bulldog
- Lhasa Apso
- Basset hound
- Cocker spaniel
- Labrador retriever
- German shepherd
- Doberman pinscher
Treatment of IVDD
If the disease is in its early stages, and the neurologic symptoms are mild, your veterinarian may recommend conservative treatment in the form of pain medication and strict exercise confinement. Many of these patients may require surgery down the road.
Patients who undergo surgery will have the bone overlying the spinal cord, and the disc material compressing the spinal cord, removed. This will be followed by several days of hospitalization, pain management, physical therapy, and possible bladder management. Owners will need to continue physical therapy and exercise restrictions for a specified amount of time after the pet is discharged from the hospital.
Prognosis of IVDD can vary depending on how significant the injury, the location of the injury, and the lapse of time between injury and treatment. Most dogs that are still walking, or still have pain sensation in their legs, have a good prognosis and will regain use of their legs and bladder function. With pets who no longer have pain sensation in their legs at the time of presentation, there is a higher likelihood that they may never walk again.