Intervertebral Disk Disease in Pets (IVDD)

— By Dr. Gabriela Castillo, DVM —

Intervertebral disk disease, or IVDD, is a common neurologic (nerve) disorder that occurs primarily in dogs and rarely in cats. It occurs when an intervertebral disk ruptures and compresses the spinal cord.

The spinal cord is protected by the vertebrae, which are the bones of the spine. In between each vertebra is a disk that acts as a cushion between the bones. These disks can weaken over time and eventually or suddenly rupture, causing compression of the spinal cord.

Compression of the spinal cord disrupts the nerve tracts, which are responsible for connecting the body to the brain. This connection is responsible for the ability to use and feel our limbs, recognize when our bladder is full, and allow us to willingly express the bladder, amongst other things. In severe cases, patients lose entirely the connection between their brain and their limbs, which is also known as paralysis.

The two types of IVDD: Hansen Type I and Hansen Type II

Hansen Type I occurs most commonly in younger, chondrodystrophic dog breeds (short legs and a longer body) such as Dachshunds, Corgis, Shih Tzus, and Bassett Hounds. Over time, the disk begins to calcify/weaken and will suddenly rupture, often due to a high-impact activity- jumping, climbing stairs, etc. Type I causes acute direct damage and compression of the spinal cord.

Hansen Type II occurs in older, larger breed dogs, including Labrador Retrievers, German Shepherds, and Dobermans. The disk degenerates over a long period of time and will bulge outwards, causing compression of the spinal cord. Typically, there is no acute onset of clinical signs usually seen with Type I.

The Symptoms

The most common clinical signs associated with IVDD include pain in the neck/back, loss of motor function of the limbs, and a knuckled-over appearance of the paws. These signs can occur suddenly and may progress over time.

When a pet comes in with the clinical signs noted above a complete orthopedic and neurologic exam will be performed to look for an inciting cause. If IVDD is suspected, further diagnostics testing will be recommended. IVDD is diagnosed with advanced imaging, such as an MRI or a CT scan, which will require a referral to a specialty hospital. However, x-rays of the spine are commonly performed to screen for other abnormalities of the spine, such as a fracture, infection, and cancer.

Treatment

There are two mainstays of treatment for IVDD. The first is medical management which focuses on pain management and strict rest for approximately 2-4 weeks. Medical management aims to allow the body to reduce the inflammation associated with the spinal cord injury and theoretically regain any lost nerve function. Success with medical management is most tremendous with mild cases of IVDD. If clinical signs do not improve in 1-2 weeks or worsen in severity, diagnostic imaging and surgery should be considered.

The second form of treatment is a surgical intervention performed by a neurologist or surgeon at a specialty hospital. Surgery is often recommended for patients who have severe clinical signs such as paralysis and those who did not improve with medical management with persistent severe clinical signs.

Prognosis

The prognosis for a patient with IVDD is dependent on the severity of clinical signs and the type of treatment performed. As previously stated, patients with mild cases of IVDD have a good prognosis with medical management. Surgical intervention typically carries a good prognosis with reported 85-95% of patients regaining their ability to walk after surgery.

If you have any questions or concerns during this time, please do not hesitate to contact us here at Metro Paws Animal Hospital. We are always happy to help you!