🧠 Thoracolumbar IVDD in Dogs: Vet-Approved 2025 Guide to Spinal Disc Herniation & Signs 🐾

By Dr Duncan Houston BVSc

🔍 What Is Thoracolumbar IVDD?

Thoracolumbar Intervertebral Disc Disease (IVDD) refers to disc problems affecting the spine from the middle of the back (thoracic vertebrae) to the base of the tail (coccygeal vertebrae). IVDD is a common and painful spinal disorder in dogs that can lead to weakness, nerve pain, or even paralysis 🧠.

🦴 What Is an Intervertebral Disc?

Between each vertebra in your dog’s spine is a disc made of two parts:

• 💪 Annulus fibrosus – Tough, fibrous outer shell
• 🧊 Nucleus pulposus – Soft, gel-like center that absorbs shock

These discs cushion movement and protect the spinal cord. But when a disc degenerates or herniates, it can press on nerves or the spinal cord—resulting in pain or mobility issues 🚫.

🧬 How Do Discs Degenerate?

Degeneration can be age-related or genetic. There are two primary processes:

🟢 Type I – Sudden Herniation

• ⚠️ Common in Dachshunds, Pekingese, Shih Tzus
• 🧱 The disc calcifies and then bursts outward (extrudes)
• 💥 Causes severe, sudden signs—often needs surgery

🟠 Type II – Gradual Protrusion

• 🐕 Seen in older, large-breed dogs like German Shepherds
• 📉 The outer layer weakens and bulges upward over time
• 🔁 Can cause chronic, progressive nerve compression

💥 Disc Herniation: Types

• 📦 Protrusion: Bulge of disc into spinal canal
• 💣 Extrusion: Inner disc explodes through outer ring into spinal cord space
• ⚡ ANNPE: Sudden jelly-like rupture with high impact (non-compressive)

Disc herniation usually happens without warning. Pet parents often report signs starting after a fall or jump—but in reality, the herniation often occurred before the movement 🐾.

📋 Signs of Thoracolumbar IVDD

Symptoms vary depending on severity, disc location, and compression:

🟡 Mild Signs

• 😣 Back pain or sensitivity
• 😓 Hunched back posture
• 🚷 Reluctance to play, jump, or climb stairs
• 🦵 Limping or paw licking (root signature)

🔴 Advanced Signs

• 🧍 Incoordination (ataxia)
• 🚫 Hind limb weakness or dragging
• 💩 Urinary or fecal incontinence
• 🛌 Paralysis or inability to stand

Any sudden loss of walking ability is a veterinary emergency. Seek help immediately for the best outcome ⏱️.

🧠 What’s a Root Signature?

If your dog is limping, holding up a leg, or licking at a paw but X-rays of the limb look normal, the cause might be nerve root compression from IVDD. This is called a root signature—a sign that pain signals are originating in the spine, not the limb itself 🔎.

⚠️ Severity of Spinal Compression

The more compression there is—and the faster it happens—the worse the symptoms. Sudden extrusions tend to cause more severe neurological damage than slow, chronic protrusions 🧬.

⚠️ Serious Complication: Myelomalacia

In rare cases, a herniated disc can lead to spreading spinal cord death—called myelomalacia. This is rapidly progressive and unfortunately, often fatal. Prompt diagnosis and monitoring are essential 🚨.

📲 Ask A Vet if You Notice These Signs

If your dog shows back pain, stumbles, or drags their legs, don’t wait. Visit AskAVet.com to speak to a licensed vet and determine if IVDD is likely 🐾.

• 💬 Symptom review and urgency assessment
• 🧠 Referral guidance for imaging or surgery
• 📋 Pain management and crate rest planning

📱 Download the Ask A Vet App to connect with Dr Duncan Houston and our team any time your dog shows possible spinal signs 🐶.

💚 Final Thoughts

Thoracolumbar IVDD is serious—but with early intervention, proper diagnosis, and the right treatment plan, most dogs recover well. Understanding how this disease works helps you make timely, informed decisions and avoid long-term consequences for your dog’s mobility and quality of life 🦴.

Need support? Visit AskAVet.com or open the app to chat with a vet today 🩺.