IVDD stages and grades explained
Owners often hear “stage 2”, “grade 4” or “deep pain negative” and assume there is one universal scale. In reality, veterinary studies and hospitals use more than one grading system. The important idea is the dog’s neurological function, not the number alone.
A practical owner-facing severity ladder
Pain with normal walking
The dog can walk normally but has spinal pain or a guarded posture.
Walking but weak or uncoordinated
The dog remains ambulatory but may sway, cross feet, scuff paws or appear weak.
Unable to walk independently
There is voluntary movement, but the dog cannot take normal unsupported steps.
Paralysis
Voluntary movement in affected limbs may be absent. Veterinary assessment of pain perception becomes an important prognostic factor.
Why numbers can be confusing
One commonly cited research scale runs in the opposite numerical direction to popular owner-facing “stage 1–5” descriptions. For example, a modified Frankel scale described in the Canine Spinal Cord Injury Consortium review grades normal dogs at the high end and dogs without pain perception at the low end. This is why Aubenord will always describe the actual function next to any grade.
What matters more than the label?
- Whether the dog can walk independently.
- Whether voluntary limb movement is present.
- Veterinary assessment of pain perception.
- Where the spinal injury is located.
- Imaging findings and whether spinal cord compression is present.
- How the signs are progressing.
- Other health issues and the treatment selected.
Do not grade your dog at home
Owners can report what they observe, but determining neurological grade — especially deep pain perception — is a clinical examination. Do not pinch toes or use painful stimuli yourself.
Canine Spinal Cord Injury Consortium — current approaches to acute thoracolumbar disc extrusion
ACVS — IVDD
This is educational information and should not be used to assign a neurological grade or make a treatment decision without veterinary assessment.