What Is IVDD in Dogs?
Intervertebral Disc Disease (IVDD) in dogs is a neurological ailment affecting the spinal cord, vertebrae, and the intervertebral discs—the soft, jelly-like material between each vertebra. These discs act as cushions, absorbing shock and facilitating movement.
IVDD arises when these discs bulge or rupture, encroaching upon the space occupied by the spinal cord. This compression can result in pain, nerve damage, and potentially paralysis. Commonly referred to as a slipped, herniated, or bulging disc, IVDD predominantly affects breeds with elongated backs and short legs, such as Dachshunds, Basset Hounds, and Shih Tzus. However, larger breeds like German Shepherds may also be susceptible due to age-related disc degeneration.
Types
There are two primary types of Intervertebral Disc Disease (IVDD) in dogs: Hansen Type I and Hansen Type II. Each type affects the intervertebral discs differently, leading to painful pressure on the spinal cord:
Hansen Type I occurs when the inner, jelly-like part of the disc hardens. A sudden movement, such as a jump or impact, can cause this hardened disc to rupture through its outer shell and compress the spinal cord and surrounding nerves. This herniation results in acute, intense pain and varying levels of reduced nerve function. Dachshunds and similar breeds with similar body structures are most commonly affected by Type I disc disease.
Hansen Type II, on the other hand, involves a slower degenerative process. Over months to years, the disc material gradually compresses the spinal cord and nerves as the fibrous outer layer weakens and collapses. This leads to more persistent, long-term pain and spinal cord compression. Type II disc disease is prevalent in large breed dogs like German Shepherds.
Symptoms
The symptoms of Intervertebral Disc Disease (IVDD) in dogs vary depending on the type of disc herniation and its location along the spinal column. The spine consists of five regions—cervical, thoracic, lumbar, sacral, and caudal vertebrae. The most frequent sites for disc herniation in dogs are at the end of the thoracic vertebrae (T11-T12) and the beginning of the lumbar vertebrae (L2-L3), causing pain and affecting mobility. Although less common, cervical herniations (in the neck) occur predominantly in breeds like Dachshunds, Beagles, or Poodles, often resulting in intense pain but relatively less loss of function.
Symptoms of IVDD may include:
- Limping or lameness
- Unsteady walking
- Dragging of the back legs
- Stumbling over the back feet
- A hunched back or neck with tense muscles
- Weakness
- Pain
- Reluctance to jump
- Anxious behavior such as shivering or panting
- Reduced activity level
- Decreased appetite
- Loss of bladder and/or bowel control (urinary and/or fecal incontinence)
- Difficulty posturing to urinate or defecate
- Paralysis, indicated by complete loss of function in the front or hind limbs.
Causes
The development of Intervertebral Disc Disease (IVDD) in dogs is primarily attributed to a herniated disc and subsequent compression of the spinal cord. In chondrodystrophic breeds, like Dachshunds, Corgis, and Bassett Hounds, IVDD often arises from an acute or sudden rupture of the disc material. Despite wear and tear gradually weakening the disc, the rupture typically occurs abruptly due to forceful impacts such as jumping or landing.
Contrarily, in larger breeds such as Shepherds, Labradors, and Doberman Pinschers, the discs undergo a gradual hardening process over time. Eventually, this hardening leads to bulging or rupturing, resulting in compression of the spinal cord. Unlike in chondrodystrophic breeds, this type of IVDD develops gradually, and there isn’t usually a single forceful impact responsible for the damage.
Diagnosis
If you notice any signs of back pain or difficulty in your dog’s mobility, it’s crucial to promptly seek veterinary attention. Early intervention increases the likelihood of a successful recovery from Intervertebral Disc Disease (IVDD).
Your veterinarian will conduct a comprehensive physical and neurological examination, along with baseline blood and urine tests to evaluate your dog’s overall health. If IVDD is suspected, imaging tests will likely be recommended to assess the severity of the condition and visualize the spine and surrounding tissues.
Plain radiographs (X-rays) will be taken to examine the vertebrae for any narrowing joint spaces, although they don’t show the spinal cord itself. Magnetic Resonance Imaging (MRI) is preferred for diagnosing IVDD as it provides detailed images of the spine, allowing for accurate identification of spinal cord compression and disc material in the vertebral canal. MRI scans enable assessment of both the discs and spinal cord within a single image. Depending on the clinical signs and the need for surgical intervention, additional diagnostic tools such as myelography or computed tomography (CT scan) may be used to further investigate the type and location of disc herniation.
Treatment
Treatment for Intervertebral Disc Disease (IVDD) in dogs varies depending on the severity of spinal cord damage, ranging from medical management to emergency surgical intervention.
In mild cases, the focus is on alleviating pain, inflammation, and swelling through medication and strict confinement. Dogs are typically confined to a crate or small area to prevent any strenuous activity, with the duration of rest determined by the specific injury and healing rate. Physical therapy may also be recommended to aid in recovery.
For more severe cases involving paralysis, surgical correction of the herniation is often necessary. This surgery is usually performed urgently to minimize permanent neurological damage. The objective is to assess the herniation and relieve pressure on the spinal cord by removing a portion of the bony vertebra, known as a laminectomy.
Post-surgery, activity restrictions remain crucial to facilitate healing of the spinal cord. Despite surgical intervention, some dogs may not fully regain function and may experience lasting neurological issues.
Living and Management
The recovery and management of Intervertebral Disc Disease (IVDD) in dogs depend significantly on the extent and location of the injury. In most cases of disc ruptures, minimal neurological issues are involved, providing the dog with an excellent chance of regaining walking abilities. However, if the pet has lost sensation in its legs before surgery, the likelihood of walking again may be diminished.
The spinal cord heals gradually, necessitating careful restrictions on activities such as running, jumping, climbing stairs, playing with other dogs, and getting on or off furniture. For mild to moderate IVDD injuries, treatment may involve steroid and anti-inflammatory medications to alleviate pain and swelling, coupled with strict limitations on activity for about four to six weeks. Following IVDD surgery, recovery typically requires six to eight weeks of restricted activity.
It’s not uncommon, especially in Dachshunds, for dogs to experience additional disc herniations in other areas of the spine after surgery. While it’s challenging to prevent future herniations entirely, the risk can be reduced by avoiding activities that involve jumping and sudden movements, such as playing with a frisbee or navigating stairs. Maintaining a healthy weight is also essential for dogs with back issues, as it facilitates quicker recovery from surgery and reduces strain on the back.
Surgical outcomes are generally most successful in dogs who have retained their ability to walk. If surgery doesn’t fully restore normal mobility, a dog wheelchair can provide support, enabling the pup to lead a happy and active life despite living with IVDD.