Intervertebral Disc Disease
Intervertebral Disc Disease
Also known as: IVDD, Intervertebral disk disease, Hansen type I disk extrusion, Hansen type II disk protrusion, Acute intervertebral disk disease
CatDog
Intervertebral Disc Disease
Also known as: IVDD, Intervertebral disk disease, Hansen type I disk extrusion, Hansen type II disk protrusion, Acute intervertebral disk disease
In short
Intervertebral Disc Disease (IVDD) is a common, painful spinal condition in dogs and occasionally cats where herniated discs compress the spinal cord. Recognizing early signs like spinal pain and weakness is crucial, as prompt veterinary care or surgery can prevent permanent paralysis.
TL;DR. Intervertebral Disc Disease (IVDD) is a common, painful spinal condition where a herniated disc presses on the spinal cord, causing symptoms ranging from mild back pain to complete paralysis.
A cross-section showing how a herniated disc presses directly on the spinal cord.
Intervertebral Disc Disease (IVDD) is a degenerative condition affecting the shock-absorbing cushions, or discs, that sit between the bones of the spine (vertebrae). Each disc consists of two main parts: a tough, fibrous outer ring called the annulus fibrosus, and a soft, gelatinous center called the nucleus pulposus. In a healthy animal, these discs allow the spine to bend, flex, and absorb the impact of daily activities like running, jumping, and walking.
When IVDD occurs, these discs undergo degenerative changes that compromise their structural integrity. This degeneration typically leads to one of two types of herniation, historically classified as Hansen Type I and Hansen Type II:
Regardless of the type, the resulting pressure on the spinal cord disrupts the transmission of nerve signals between the brain and the rest of the body. This leads to severe pain, loss of coordination, and, in severe cases, permanent paralysis. While predominantly diagnosed in dogs, IVDD can also occur in cats, though it is far less common in the feline population.
The primary driver of IVDD is genetic predisposition, particularly in chondrodystrophoid breeds—dogs bred for short legs and long bodies. In these dogs, abnormal cartilage development causes the intervertebral discs to age and degenerate prematurely, often within the first year of life.
As noted in a leading veterinary internal medicine reference:
"With normal aging the nucleus is gradually replaced by fibrocartilage. In some dogs, particularly the chondrodystrophoid breeds, the nucleus matrix degenerates, dehydrates, and mineralizes, making these dogs prone to acute disk rupture."
— Internal Medicine, p. 1087
While genetics play the largest role, physical trauma, repetitive strain from jumping off high furniture, and obesity also contribute to disc failure. Excess body weight places continuous, abnormal mechanical stress on the spinal column, accelerating the wear and tear on already vulnerable discs.
The clinical signs of IVDD depend on the location of the affected disc (usually the neck or the mid-to-lower back) and the severity of the spinal cord compression. Symptoms can appear suddenly or progress gradually over several weeks.
An arched back (kyphosis) is a common sign of spinal pain in dogs with IVDD.
Your vet will begin with a comprehensive physical and neurological examination. During this exam, they will assess your pet's reflexes, check their conscious proprioception (paw-flipping test), and carefully palpate the spine to locate the source of pain. This helps the vet determine the general area of the spinal cord lesion.
To obtain a definitive diagnosis, advanced imaging is required:
"MRI is the best diagnostic method for localizing the site and the side of extruded disks with nearly 100% accuracy... MRI also allows evaluation of the cord parenchyma for injury and edema, which may be associated with prognosis for recovery in patients with loss of deep pain sensation."
— Internal Medicine, p. 1089
Treatment for IVDD is categorized into conservative (medical) management and surgical intervention. The choice depends on the severity of the neurological signs, the level of pain, and how long the symptoms have been present.
Conservative management is typically reserved for pets with mild neurological deficits (such as mild weakness or knuckling) and those who still have intact pain sensation.
Surgery is indicated for pets with severe neurological deficits, progressive worsening of symptoms despite medical therapy, or recurrent episodes of spinal pain. The most common procedure is a hemilaminectomy (for back discs) or a ventral slot (for neck discs). During surgery, the veterinary surgeon removes a portion of the vertebral bone to access the spinal canal and carefully extracts the herniated disc material, relieving the pressure on the spinal cord.
Following surgery, intensive physical rehabilitation—including passive range-of-motion exercises, laser therapy, and underwater treadmill therapy—is highly beneficial to help the pet regain strength and coordination.
The prognosis for pets with IVDD is highly dependent on their neurological status at the time of presentation, particularly whether they can still feel deep pain.
For dogs with intact deep pain sensation, the prognosis is generally good to excellent, with an 80% to 95% success rate for recovery, whether treated conservatively or surgically. However, if a pet has lost deep pain sensation, the prognosis drops significantly. In these cases, conservative management yields less than a 10% success rate, while prompt surgical decompression offers approximately a 64% chance of recovery.
If the spinal cord undergoes a rare but devastating process called progressive myelomalacia, the prognosis becomes hopeless. As described in veterinary texts:
"In approximately 10% of dogs presenting for rapid-onset complete paralysis and loss of deep pain perception, focal spinal cord damage and edema result in spinal cord ischemia and progressive myelomalacia of the cord cranial and caudal to the original lesion (i. e. , ascending descending)"
— Internal Medicine, p. 1092
Myelomalacia is the progressive dying of spinal cord tissue. It is irreversible, painful, and ultimately fatal as it ascends to the nerves controlling respiration.
For feline patients, long-term prognosis data is limited due to the rarity of the condition in this species. However, clinical guidance is extrapolated from canine protocols, and recovery rates similarly depend on the severity of the initial spinal cord injury.
MRI is the gold standard for identifying the exact location of disc herniation.
While you cannot change your pet's genetics, you can take steps to minimize the risk of disc herniation:
There are currently no reliable genetic screening tests available to predict which individual dogs will develop clinical IVDD, making lifestyle management the primary line of defense.
IVDD can progress rapidly. If your pet shows any of the following signs, contact your veterinarian immediately. Treat these as emergencies:
Delaying treatment, especially once a pet has lost the ability to walk, can significantly reduce the chances of a successful recovery.
Chondrodystrophoid breeds are highly predisposed to Hansen Type I IVDD. These include the Dachshund, Basset Hound, Beagle, [Cardigan Welsh Corgi](/p/breeds/cardiganwelshcorgi_dog), Welsh Corgi, Chihuahua, Chinese Shar-Pei, Shar Pei, Lhasa Apso, Pekingese, Shih Tzu, Toy Poodle, and Miniature Schnauzer.
Non-chondrodystrophoid breeds, such as the Doberman Pinscher, Dalmatian, Rottweiler, [English Cocker Spaniel](/p/breeds/englishcockerspaniel_dog), Cocker Spaniel, Staffordshire Bull Terrier, German Shepherd Dog, Labrador Retriever, and Border Collie, are more prone to the slowly progressive Hansen Type II IVDD.
Additionally, a highly specific hereditary spinal condition occurs in young Shiloh Shepherds:
"A similar syndrome with degeneration and bony proliferation of multiple thoracolumbar articular facets causing spinal cord compression has been reported as a hereditary condition in 4- to 10-month-old Shiloh Shepherds."
— Internal Medicine, p. 1099
If you own one of these predisposed breeds, maintaining a lean body weight and implementing spinal safety measures early in life is highly recommended.
Treatment must be prescribed by a licensed veterinarian based on your pet. Specific drug doses are intentionally not shown here.
Intervertebral Disc Disease (IVDD) is a common, painful spinal condition in dogs and occasionally cats where herniated discs compress the spinal cord. Recognizing early signs like spinal pain and weakness is crucial, as prompt veterinary care or surgery can prevent permanent paralysis.
Spinal pain、Arched back、Ataxia、neck pain、paraparesis、proprioceptive deficits、tetraparesis、Loss of deep pain perception
MRI、CT、Myelography、Neurologic examination、Survey radiographs of the spine
Treatment must be prescribed by a licensed veterinarian based on your pet. Specific drug doses are intentionally not shown here.
This article is for general education and is not a substitute for professional veterinary advice. If your pet is unwell, please consult a veterinarian.
Peqaboo’s AI helps you track symptoms, understand lab reports, and know when to see a vet.
Get the Peqaboo app