IVDD Stages in Dogs: What Each Grade Means and What the Odds Are

IVDD is staged by what your dog can still do, not by how bad the disc looks on a scan. The five stages run from pain with a normal walk, through a wobbly walk, to being unable to walk, to full paralysis, to paralysis with the loss of deep pain sensation. Each step down changes both the treatment conversation and the odds.

Before any of that, though, there is a problem with the numbers themselves, and it catches people out constantly.

Your Vet's Grade May Mean the Opposite Somewhere Else

At least three staging scales are in active use, and two of them run in opposite directions.

An owner told their dog is a grade 5 by a clinic using the first scale, who then reads a paper using the second, will conclude their dog is nearly normal. It is the opposite.

The 2022 veterinary consensus statement on this condition sidesteps the whole problem by not using numbers at all. It uses four plain descriptions: spinal pain only or walking wobbly, unable to walk, paralysed with deep pain present, paralysed with deep pain absent. Those categories are what the outcome data is actually built on.

Ask your vet which scale they are using, and when you talk to anyone else about your dog, describe what the dog can do rather than quoting a number.

The Stages, in Plain Terms

What follows uses the common 1 to 5 scale, since that is the one most owners are given.

Stage 1: pain only

The walk is normal or close to it. What you see is discomfort: a hunched back, a tucked belly, trembling, yelping when lifted, reluctance to jump, a dog that cannot get comfortable. With a neck disc it looks like a stiff neck, a lowered head and reluctance to look up.

This is the stage where the diagnosis is most often missed, because the dog is walking and the signs read as a strained muscle or a bad mood.

Stage 2: walking, but wobbly

The back legs still work but no longer place accurately. The gait staggers, the legs cross over, and the classic sign is a paw folded over onto its top surface with the dog not correcting it. Vets describe the overall picture as a drunken sailor walk.

Stage 2 is the point at which this stops being a wait and see. The dog is still walking, which reassures owners, but the spinal cord is now clearly involved.

Stage 3: cannot walk unassisted, legs still move

The dog cannot get up and stay up, but there is still deliberate movement in the back legs. Supported by a towel under the belly, it will try to step.

This distinction between deliberate movement and reflex twitching matters. A deliberate step is the dog trying to walk. A jerk when the foot is touched is not.

Stage 4: paralysed, deep pain present

No voluntary movement in the back legs at all. Bladder control has usually gone too. But when the vet tests deep pain sensation, the dog responds.

Stage 4 sounds catastrophic and is far more recoverable than it looks. That is the single most useful thing on this page for anyone whose dog is here right now.

Stage 5: paralysed, deep pain absent

The same as stage 4, but the dog no longer consciously registers a firm pinch on the toes. This is the stage that changes the odds sharply, and it is also the stage with the highest risk of the serious complication described further down.

Why Deep Pain Is the Line That Matters

Everything above stage 4 is a matter of degree. The line between stage 4 and stage 5 is a different kind of line, because it is the strongest single predictor of whether a dog walks again.

Deep pain perception is tested by applying firm pressure to the toes with an instrument and watching for a conscious response: vocalising, turning to look, trying to move away.

Here is the mistake almost every owner makes. A dog pulling its leg away is not evidence of deep pain. Leg withdrawal is a spinal reflex that keeps working when the connection to the brain is severed. A dog with no deep pain sensation at all will still snatch its foot back from a pinch, every time.

Owners see that, feel reassured, and wait. It is not a test to attempt at home: it hurts, a frightened dog in pain may bite, and reading it correctly takes training.

What Each Stage Means for the Odds

This is where staging earns its keep, because the recovery figures differ enormously across it. These come from the 2022 veterinary consensus statement.

Two things jump out of that table that owners are rarely told.

At stages 1 and 2, crate rest gets four out of five dogs there. Surgery is better, but the gap is narrow enough that cost, anaesthetic risk and your own circumstances are legitimate parts of the decision.

At stage 5, surgery still recovers 61 percent. That is a poor prognosis. It is not the hopeless one many owners are given, and it is worth a second opinion from a neurologist before accepting that nothing can be done.

How Fast Stages Change, and in Which Direction

In a Type I disc extrusion, the kind that happens in short legged breeds, the progression from stage 1 to stage 5 can take hours. That is why an owner who saw a hunched, painful dog in the morning can be looking at a paralysed one by evening.

In a Type II protrusion, the slow bulging kind seen in larger breeds, the same journey can take years and may stall permanently partway.

Recovery generally runs back up the same ladder in reverse: deep pain returns, then deliberate movement, then supported standing, then wobbly walking. Owners find it useful to know the order, because seeing the next rung appear is the earliest real evidence of progress.

The timelines are shorter than most people fear. Median time to walking after surgery was 7.5 days in one randomised trial. Managed conservatively, the median was 11 days for dogs with deep pain intact and 25 days for those without, though both had a long tail running out to about three months.

Getting Worse After Treatment Is Not Automatically Failure, but It Is Urgent

There is one pattern that needs naming, because owners who have not heard of it are blindsided by it.

Progressive myelomalacia is a spreading destruction of the spinal cord that happens almost exclusively in dogs that have lost deep pain sensation. Reported rates among those dogs run from around 5 to 10 percent in one reference text up to 21 percent in a 2025 study, with French Bulldogs at the high end. It has no treatment and it is fatal.

It usually declares itself within 48 hours of presentation but can begin up to five days later. The signs are paralysis climbing forward up the body, loss of tail tone, changing reflexes, and eventually difficulty breathing.

So a recently paralysed dog that is going backwards rather than forwards needs re examination immediately rather than at the next scheduled check. And if it does happen, it is not caused by anything the owner did.

If your dog went down suddenly rather than declining, our guide to a dog whose back legs have stopped working covers the first hour.

What the Stage Does Not Tell You

Staging is a snapshot of function, and it is genuinely useful. But three things it cannot do are worth knowing.

It does not tell you the cause. A stage 3 dog might have a classic disc extrusion, or a spinal stroke, or an acute non compressive extrusion that bruised the cord without compressing it. Those look identical at the roadside and have different treatments and different outlooks.

It does not predict the individual. The percentages above describe populations. Plenty of stage 4 dogs walk out within a fortnight, and a few stage 2 dogs deteriorate.

It does not fix the timing question. There is no hard 48 hour cutoff after which surgery becomes pointless, whatever you read: the consensus statement says explicitly that treatment should not be declined simply because a dog has been paralysed for a long time. What is true is that delay past roughly twelve hours raises the risk of the complication above.

The wider picture, including treatment options, medication and what strict rest actually involves, is in our guide to IVDD in dogs.

What Life Looks Like at Each Stage

Stages 1 and 2. The whole job is confinement. At least four weeks in a crate or a small room with no furniture, out only on a lead to toilet. No stairs, no sofa, no off lead time. The hardest part is that a dog on pain relief feels fine and wants to move, which is precisely the danger. Painkillers without confinement are actively contraindicated.

A dog wheelchair for back legs is not part of any of the early stages, and that is worth stating before the section that describes them.

Stage 3. Add support for getting outside. A towel or sling under the belly to take weight off the back end for toilet trips, on a short predictable route with grip underfoot.

Stages 4 and 5. The bladder becomes the real work. A paralysed dog usually cannot empty its own bladder and needs it expressed several times a day, which has to be taught hands on by your vet. Watch for infection: in one study following dogs for three months after disc surgery, 38 percent developed a urinary tract infection, most between weeks one and six, and 60 percent of those were invisible on a routine urine test. A culture is what finds them.

On physiotherapy. Basic rehabilitation is safe and recommended. The one randomised trial comparing basic against an intensive fourteen day programme after surgery found no difference in how fast or how fully dogs recovered, so an expensive intensive package has not been shown to beat the simple version.

The through line across all of that is that a stage is a starting point for a plan, not the plan itself.

On wheels. Not during the confinement period, whatever the stage, because that period is about restricted activity and a cart is the opposite of it. After that, whether a cart is right depends on where recovery has plateaued rather than on the stage the dog started at, which our guide to wheelchairs for IVDD dogs covers in detail.

What changes at that point is the goal. You stop trying to rebuild the walk and start substituting for it.

For dogs that plateau at stage 4 or 5 and stay there, the Whisker Bark adjustable dog wheelchair is what returns the walk, and the adjustability matters because a dog recovering unevenly needs the height changed as it changes.

The stage a dog starts at matters far less than the direction it is moving, and that is the thing to keep measuring week to week.