Just like people, dogs can often develop back problems during their lifetimes. Intervertebral Disk Disease (IVDD) occurs when discs in the dog’s spine deteriorate, collapse, bulge out, rupture, herniate or become displaced. These issues cause gradual degeneration of the dog’s spine due to physical abnormalities, obesity, genetics, repetitive trauma or other factors. IVDD is one of the most common neurological disorders seen in the dog. There are three forms of IVDD: Hansen Type I, Hansen Type II, and Hansen Type III High Velocity.
Hansen Type I disc disease is most common in small breed dogs that are two years old or older. Larger breeds can also be affected. With this condition, the center of the vertebrae, which should be a jelly-like substance, becomes calcified and hardened. With a sudden jump or other movement, this hardened center can push out of the vertebra disc, like jam bursting out of a donut. This compresses the spinal cord and nerves, resulting in pain or even paralysis. The velocity of the impact often determines the severity of the injury.
Hansen Type II disc disease in dogs is more similar to disc disease in humans. Instead of an extrusion in the center of the disc, there is a bulging and protrusion of the annulus, or outer part of the disc. Most dogs show signs of Hansen Type II disc disease right away, but some develop the condition more gradually. In these dogs, you may notice reluctance to exercise, rise, jump or climb stairs. They may also look stiff or have a hunched back. Medium to large breed dogs, ages five to 12 years old, tend to be the most affected by this type of disc disease.
Hansen Type III disc disease results from heavy exercise or trauma, causing a normal spinal nucleus to explode due to a sudden tear in the outer part of the disc. This injury does not result in ongoing spinal cord compression and with rehabilitation and physical therapy; dogs can usually recover without surgical intervention.
Dogs with IVDD have symptoms ranging from mild pain (lowered head, reluctance to move, stiffness, sensitivity to touch), to severe pain (arched back, lameness, dragging legs, inability to stand, crying when touched or moving, trembling, staggering, and collapse). They could also experience partial or complete paralysis. Very severe cases may develop myelomalacia (softening and dying of the spinal cord), which can be fatal.
Other diseases can mimic the signs of spinal cord disease, so a thorough neurological examination by a veterinarian and a MRI are needed for diagnosis.
Surgical and nonsurgical treatment options are available for IVDD. For dogs with a first episode of back pain, a conservative approach of cage rest, medications and even acupuncture are usually the first recommended course of care. Dogs with more severe signs are best managed with surgery to decompress the spinal cord. Rehabilitation after surgery is important and will help patients heal, regain muscle strength and improve their ability to walk.
Have your dog examined at the first signs of IVDD. Early intervention could prevent a back injury from becoming even more serious and help your dog to regain a more active and happy lifestyle.