Degenerative Hansen Type II Disc Disease in Dogs

Diseases of the spine, such as Hansen Type II disc disease, interfere with a dog's ability to stand, sit and move. The condition most commonly presents in large dogs who are in their advanced years, while younger dogs of certain breeds, including the dachshund, shih tzu and beagle, who exhibit pain related to spinal issues are more likely diagnosed with Hansen's Type I, rather than Type II.

The spine of all vertebrates supports the body at rest and when active. The dog's spine consists of seven cervical (neck) vertebrae, 13 thoracic (chest) vertebrae, seven lumbar (lower back) vertebrae, three sacral vertebrae, which are fused, and a variable number of tail vertebrae. Each vertebrae is "cushioned" by intervertebral discs that provide support and flexibility in the spine, but when these discs are damaged, the protrusion of materials in the discs (herniation) place pressure on the spine and nerves, creating pain and even paralysis.

Two types of disc disease are seen in dogs, Hansen Type I and Type II. In Type II, disc degeneration is usually more gradual, and the annulus fibrosus fibers become soft and put pressure on the spinal cord over time. Hansen Type II has been compared to normal aging processes. When veterinarians examine older dogs with spinal weakness, they perform a neurologic physical exam, where the doctor tests reflexes, pain responses and strength to locate the problem. Radiographs, or X-rays, can confirm the presence of disc degeneration, and CT scans, MRI or myelograms may be ordered to give more details. With the images shown on these tests and reports, doctors can make accurate diagnoses and treat their patients accordingly. ,

Although disc herniation can occur anywhere on a canine's spinal cord, the most common sites include the T11-T12 and L2-3 regions, as well as the cervical intervertebral disc C2-C3 and the L7-S1 intervertebral disc space in the lower lumbar region, according to the Animal Medical Center of Southern California. Male dogs are commonly more susceptible to Hansen's Type II than females. The area near the damaged disc maybe be painful to the touch, and dogs may exhibit symptoms, such as avoiding social interactions with other pets, whimpering from pain and refusing meals. Treatment options include medical management, physical therapy and surgery, depending on what is discovered through testing.

If the dog can walk, therapy and medication may offer relief. The veterinarian might recommend non-steroidal anti-inflammatories (NSAIDs), muscle relaxants and steroids to help ease symptoms, and limit the dog's activity by putting him on cage rest for several weeks to reduce swelling and pressure on the nerves. In advanced cases, especially where the dog cannot walk, surgery may be the best choice to help the dog recover, according to Wendy C. Brooks, DVM, an educational director for VeterinaryPartner.com.