What do the IVDD grades mean?

Vets grade IVDD by what a dog can still do, not by what a scan shows. Can they walk? Can they feel their feet? Have they lost bladder control? The answers put a dog somewhere on the IVDD grades, a scale that runs from "sore" to "emergency."

If someone used a number at you, and you nodded and then looked it up in the car park, this is the plain version.

What the IVDD grades describe

Practices use slightly different wording and numbering, so ask yours which scale they're using. But they all describe the same progression, in the same order.

Pain only. The dog walks normally but is clearly uncomfortable. Reluctant to jump, tense through the back, yelping when picked up a certain way.

Walking, but wobbly. Coordination is affected. You see scuffing, back legs crossing over, a slightly drunk quality to the back end.

Can't walk, but still moving the legs. The legs move, but the dog can't get their weight over them.

No voluntary movement in the back legs, though feeling is still there.

Loss of deep pain sensation. The most serious, and the most urgent.

The line that matters more than the others

If you take one thing from this page: deep pain sensation is the line vets care about most.

It's the deepest level of feeling in a limb and the last thing to disappear. A dog who still has it is in a very different conversation from a dog who doesn't, and for the dog who's lost it, the window where surgery does the most good is counted in hours.

It's also why this can't be checked at home. Testing it properly is a specific clinical examination, and a dog pulling their leg away when you touch it is not the same thing. If you're worried about this, that's a phone call today, not a question for the internet.

Why how fast it happened matters

Two dogs can land at the same grade and face completely different odds.

A dog who went from normal to unable to walk over four hours has a different injury from one that got there over four weeks, even though they look identical today. Speed of onset tells your vet about the nature of what happened, and it shapes the plan as much as the grade does.

So when you get asked "when did you first notice?", that question is doing real work. Be as precise as you can.

When it's urgent

Go straight to your veterinarian if your dog suddenly can't stand or walk, has lost control of their bladder or bowels, or is in severe pain, especially if any of it came on over hours. That's an emergency, and time changes what's possible.

One thing to do today

Write down the date you first noticed something, and what it was.

Not "a few weeks ago." An actual date and the actual thing: October 2nd, hesitated at the bottom of the stairs. Put it in your phone notes.

You'll be asked this more than once, and memory reshapes itself badly under stress, it tends to compress timelines and move things closer to the present. A note written before you were frightened is more accurate than a recollection made afterwards, and it genuinely affects decisions made about your dog.

Where rehabilitation fits

Grading is a veterinary job, and so is choosing between surgery and conservative management. Neither is a rehabilitation decision, and we wouldn't pretend otherwise.

What we do is what comes after either path. Rebuilding the muscle lost during confinement. Restoring normal movement. Getting a dog back on their feet with some confidence. For some dogs that means learning to walk again. For others it means undoing the careful, protective way of moving they adopted while they hurt, which, left alone, quietly becomes permanent.

If your dog's been given a grade and you want to know what rehabilitation would actually involve, call and tell us where things stand. We'll be straight with you about what it can and can't do.

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Related reading: IVDD in dogs: surgery isn't the only path · Can a dog recover from IVDD without surgery? · When your dog's back legs start giving out · How long is crate rest for IVDD, and how do you get through it?

Questions Pet Parents ask

What are the IVDD grades in dogs?

Grading describes how badly the spinal cord is affected, based on what a dog can still do. Broadly it runs from pain only, through wobbliness, to being unable to walk, to no voluntary movement in the back legs, and finally to loss of deep pain sensation. Practices use slightly different wording and numbering, so ask your own veterinarian which scale they mean.

Which IVDD grade needs surgery?

There's no single cutoff that applies to every dog. In general, dogs who are painful but still walking are often managed conservatively, while dogs who can't walk, or who are getting worse quickly, are more likely to be referred for surgery. How fast the signs appeared matters as much as how severe they are.

What is deep pain sensation and why does it matter so much?

It's the deepest level of feeling in the limb, and it's the last thing to go. A dog who has lost it has a much more serious injury, and the situation becomes urgent, the window where surgery helps most is measured in hours. It's the single line that changes the conversation most.

Can a dog move between grades?

Yes, in both directions. A dog can get worse over hours, which is why a sudden change needs a same-day call rather than a wait-and-see. They can also improve, which is what treatment is for. The grade describes today, not a permanent label.

Does a higher grade mean my dog won't recover?

Not on its own. Grade is one input alongside how quickly it came on, how long the signs have been there, and how your dog responds to treatment. Plenty of dogs at the more severe end do well. Your veterinarian is the right person to give you a prognosis for your particular dog, because they can assess things that can't be judged from a description.