Slipped Disc in Dogs

Dogs of certain breeds, such as the Dachshund or French Bulldog, are very prone to slipped discs at a young age and can become paralyzed practically overnight. But there's no need to panic, since, unlike people, paralyzed dogs have a fairly good chance of walking again with proper surgical treatment and rehabilitation.

In this article we'll explain in a very simple way how slipped discs happen, what symptoms they can cause in a dog, and what treatment to follow to help a paralyzed dog walk again. Shall we get started?

What is a slipped (herniated) disc?

To understand what a slipped disc involves, we need to know the anatomy of a dog's spine. A dog's spine is made up of vertebrae joined one after another. Each vertebra has a hollow space inside it, so along the spine (with one vertebra placed behind another) a canal forms, through which the spinal cord runs.

On the underside of this canal, between the vertebrae, are the intervertebral discs, whose job is to cushion the impacts the spine receives and allow movement between the vertebrae, since they have a gel-like texture.

The intervertebral disc has a roughly circular shape and is made up of an outer fibrous ring and an inner gel-like core. With a slipped disc, one of two things can happen:

• Disc extrusion (Hansen type I): The fibrous ring, due to a degenerative process, ruptures, and the core inside is pushed out into the spinal canal, causing trauma to the spinal cord and resulting in inflammation and swelling. With disc extrusions, neurological symptoms appear very quickly.
• Disc protrusion (Hansen type II): The disc gradually loses collagen with age and becomes deformed, so it can bulge into the spinal canal, causing spinal cord compression of varying severity. This compression develops progressively, so symptoms appear gradually over time.

Symptoms of a slipped disc in dogs

Depending on how severe the compression or damage to the spinal cord is, a series of symptoms will appear.

• Grade I: when there's a slipped disc but no spinal cord compression, the animal will have pain in the affected part of the spine, but no neurological signs — that is, they'll be able to walk normally.
• Grade II: when there's mild compression or damage to the spinal cord, we're looking at ambulatory paresis — that is, the animal can walk, but with difficulty. We'll notice an uncoordinated gait (ataxia), trouble standing up, or even falling from a loss of proprioception.
• Grade III: if the degree of compression or damage to the spinal cord is more severe, the animal will suffer non-ambulatory paresis — that is, they'll be able to consciously move their legs but won't be able to walk.
• Grade IV: if the spinal cord damage is deeper, the animal will suffer from plegia (paraplegia or tetraplegia) — that is, they'll lose the ability to voluntarily move their limbs, but will still have feeling in them.
• Grade V: when there's very severe damage to the spinal cord, or sections of it, the animal will be paraplegic or tetraplegic and won't feel their limbs even if we cause them pain there (loss of deep pain sensation).

How is a canine slipped disc diagnosed?

The symptoms will give the vet plenty of clues to suspect a slipped disc, especially if the symptoms are severe.

That said, the vet will perform a neurological exam to find out where along the spine the injury is. Afterward, imaging tests are done on the area of the spine suspected of having the slipped disc.

With an X-ray, a reduced space between vertebrae can sometimes be seen if there's a slipped disc, but it's not always clearly visible. Because of this, the best way to confirm the diagnosis is with a CT scan or MRI.

Treatment for a slipped disc in dogs

Treatment for slipped discs is mainly determined based on clinical signs — that is, on how severe the spinal cord damage is.

For dogs with a grade I or II slipped disc — meaning they can still walk, even with some difficulty — conservative treatment (relative rest + medication + rehabilitation) usually has a high success rate, and surgery isn't necessary.

In cases where the dog can't walk on their own (grades III, IV, and V), the treatment of choice is surgery to remove the disc material compressing the spinal cord from the spinal canal. The sooner surgery is performed, the better that dog's chances of walking again. Once decompression has been done, rehabilitation should start as soon as possible.

Rehabilitation for a slipped disc

Rehabilitation is vital for dogs with a slipped disc to recover. Even if the spinal cord compression is resolved surgically, the dog will need rehabilitation to help the damaged tissue heal and to "teach" their nervous system to walk again.

In the rehabilitation process for a dog with a slipped disc (whether operated on or resolved surgically), the following therapies are used:

• Pain relief and regeneration: although the general vet will prescribe pain relief and anti-inflammatory treatment (tramadol, gabapentin, meloxicam), the rehab vet will apply physical therapies, such as laser therapy, to reduce pain and help regenerate the damaged nerve tissue (laser therapy stimulates the formation of new connections between neurons in the spinal cord).
• Locomotor training: this therapy involves retraining gait — that is, "teaching" the nervous system how to walk. This is achieved by guiding the dog's gait on a treadmill (land-based or underwater).
• Proprioception exercises: the first thing lost with a spinal cord injury is proprioception. Proprioception is the nervous system's ability to correctly position the limbs while walking. In dogs with a slipped disc, proprioception should be trained daily (3 times a day) with exercises such as: standing the animal up (on all four legs) with the help of a support or our hands; with the dog standing, dragging their paw pads over a rough surface; stimulating the flexor reflex of the affected limbs by pinching between the toes with our fingertips until the animal flexes the limb; and so on.

Which dog breeds are more prone to slipped discs?

Breeds known as chondrodystrophic (French Bulldog, Dachshund, Basset Hound, English Bulldog, etc.) undergo very early degeneration of their intervertebral discs. From around a year of age, their discs start to degenerate, making them very prone to disc extrusions from even minor trauma to the spine, such as jumping off the sofa or a fall.

Non-chondrodystrophic breeds (especially large ones) undergo a different kind of intervertebral disc degeneration, from age-related collagen loss. Because of this, these breeds are more prone to disc protrusions from around 8-10 years of age onward.