IVDD in Dogs (Intervertebral Disc Disease) — What Every Owner Should Know

IVDD — or disc disease in dogs — is one of the most common and serious spinal conditions, affecting breeds of all sizes but most severely those with long backs and short legs. The condition occurs when the cushioning discs between the vertebrae degenerate and press on the spinal cord, causing pain, weakness and — in severe cases — paralysis. Dachshunds face a lifetime risk of up to 24%, but French Bulldogs, Shih Tzus and Beagles are also commonly affected. This guide covers the cause, types, signs by severity, diagnosis and risk factors in plain language, reviewed by Dr. Paulo Morouço, DVM.

What Is IVDD in Dogs?

IVDD occurs when the intervertebral discs — the cushions between the bones of the spine — degenerate and compress the spinal cord. In chondrodystrophic breeds, this is driven by an early process where the normal disc material is replaced by cartilage, which calcifies over time. Research has found that 46–48% of Dachshund discs show signs of calcification.

There are two main types:

Hansen Type I — Sudden rupture of the outer disc layer. Mineralised inner material escapes and compresses the spinal cord. Onset is rapid — sometimes within hours. Most common in chondrodystrophic breeds such as the Dachshund, French Bulldog and Shih Tzu. Typically affects dogs between 3 and 7 years of age.

Hansen Type II — Gradual bulging of the disc without complete rupture. Onset is slow and progressive. More common in older, larger non-chondrodystrophic breeds such as the German Shepherd and Labrador Retriever.

Signs and Symptoms of IVDD in Dogs

Signs vary depending on how severely the spinal cord is being compressed. Researchers have described three broad severity levels based on clinical presentation:

Mild (5.6% of cases):

• Spinal pain and discomfort
• Hunched posture
• Reluctance to jump on or off furniture
• Sensitivity when the back is touched
• No weakness in the legs

Moderate (25.2% of cases):

• All mild signs plus hind leg weakness
• Wobbly or uncoordinated gait (ataxia)
• Dog can still walk but stumbles
• May drag one or both hind feet

Severe (69.3% of cases):

• Unable to walk
• Complete or partial paralysis of hind limbs
• Loss of bladder or bowel control in some cases
• Deep pain sensation may be absent in the worst cases

Note: 69.3% of dogs in the DachsLife study presented with severe signs — meaning most dogs with IVDD are already significantly affected when first seen by a vet. Early recognition of mild signs is important.

Contact your veterinarian if you notice any of the following signs.

• Sudden unwillingness to jump or use stairs
• Crying out when picked up or when the back is touched
• Hunched or arched posture
• Wobbly or dragging hind legs
• Knuckling — walking on the tops of the back paws
• Loss of bladder or bowel control
• Sudden hind limb weakness or collapse

Which Dog Breeds Are Most Affected by IVDD?

The following breeds have documented IVDD prevalence data from peer-reviewed studies. Breeds marked as predisposed are confirmed at elevated risk in veterinary literature but do not yet have a single citable prevalence figure.

Dachshund IVDD is the most studied form of the disease, with prevalence data across six varieties.

Prevalence figures are from peer-reviewed studies. Predisposition confirmed means the breed is consistently identified in veterinary literature as at elevated risk. Links lead to individual breed health guides.

Risk Factors for IVDD in Dogs

Genetics: The primary driver in chondrodystrophic breeds is an overexpressing FGF4 retrogene on chromosome 12, strongly associated with Hansen Type I IVDD. Heritability of disc calcification is estimated at 0.45 to 0.53 — meaning genetics plays a major role.

Conformation: A longer back relative to height increases risk. Dogs with higher body length to height ratios have greater odds of disc extrusion and more severe signs when extrusion occurs.

Age: Most disc extrusions in chondrodystrophic breeds occur between 3 and 7 years of age. Mean age at diagnosis is 5.42 years.

Weight: Being overweight significantly increases the probability of disc extrusion. Maintaining a healthy body condition score is one of the most actionable risk factors owners can manage.

Exercise: Dogs exercising less than 30 minutes daily had higher odds of IVDD. Dogs exercising more than 1 hour daily had reduced risk. Regular moderate exercise supports spinal musculature and healthy weight.

Neutering: Neutered dogs showed increased odds of IVDD in the DachsLife study. The mechanism is not fully understood.

How Is IVDD Diagnosed in Dogs?

Diagnosis begins with a neurological examination — the vet assesses the dog's gait, pain response, reflexes and ability to feel deep pain in the hind limbs.

Imaging is then used to confirm diagnosis and locate the affected disc. Based on DachsLife 2015 data from affected Dachshunds:

• MRI — used in 39.0% of cases — the most detailed method, showing soft tissue compression clearly
• Plain radiography — used in 38.1% of cases — detects calcified discs on X-ray
• Myelography — used in 13.9% of cases — contrast dye injected around the spinal cord to show compression sites
• CT — used in 13.2% of cases — cross-sectional imaging of the spine

Radiographic screening: In predisposed breeds, plain X-rays can detect disc calcification before clinical signs appear. Calcified discs are a known risk factor for future extrusion.

IVDD in Dogs — Frequently Asked Questions