What is Intervertebral Disk Disease (IVDD) in Dogs

Intervertebral Disk Disease (IVDD) in Dogs

You might have heard the term “slipped disk” being applied to people, but did you know that dogs can get a similar disease? Vets refer to it as intervertebral disk disease, or IVDD. Aside from being incredibly painful, IVDD can also affect many everyday functions. But before we go further, a quick anatomy lesson is in order.

Your dog’s spine runs from behind their head to the tip of their tail. It is made of linked bones called vertebrae, which help protect the spinal cord. The spinal cord is important in facilitating sensation, movement and toileting.

Dog’s spine. Image courtesy Dr Buzby’s ToeGrips

What’s an “intervertebral disk” anyway?

Intervertebral disks are structures that sit between individual vertebrae, cushioning the spine and allowing for flexibility. Each disk comprises an outer fibrous layer, the “annulus fibrosus”, that encases a jelly-like core called the “nucleus pulposus”.

Cross-section of dog’s spine showing the structure of an intervertebral disk. Image courtesy VIN

How does IVDD develop?

IVDD occurs when the spinal cord is compressed by an intervertebral disk, most commonly in the neck or lower back. It is classified into two types – Hansen type I and Hansen type II – depending on how it develops.

Hansen type I IVDD often develops suddenly. The annulus fibrosus ruptures, allowing the nucleus pulposus to extend into the spinal canal and compress the spinal cord. While any dog can be affected, breeds with long backs and short legs are predisposed. Example breeds include the Dachshund, Welsh Corgi, Shih Tzu and French Bulldog.

Annulus fibrosus is light blue, nucleus pulposus is dark blue. Image courtesy Mar Vista Vet

Hansen type II IVDD is usually slower in onset. The annulus fibrosus does not rupture but degenerates with age, causing the disk to protrude into the spinal canal. It affects mostly large breeds such as the German Shepherd.

Image courtesy Mar Vista Vet

What are signs of IVDD?

IVDD causes pain and reluctance to move. Depending on severity, other signs may be noted:
- Weakness
- Uncoordinated, “drunken” walking
- Involuntary urination
- Dragging of hind legs
- Paralysis (complete inability to walk)

If you notice any of these signs, contact a veterinarian immediately. Severe pain and an inability to walk are emergencies!

The vet will examine your dog to determine the location and severity of the disease. They may also take X-rays. Referral may be recommended if the vet determines your dog might need advanced imaging and/or surgery.

How is IVDD treated?

Depending on severity, IVDD may be treated medically or surgically.
Mild cases may respond to medical treatment, which typically involves painkillers such as carprofen or gabapentin paired with several weeks of strict rest.
Severe cases, or those that do not respond to medical treatment, will require surgery.

Can IVDD be prevented?

It’s important to note that dogs who have had IVDD are prone to repeat episodes. Unfortunately, no supplement has been shown effective in preventing IVDD in predisposed breeds, as their genetics increase the susceptibility of their intervertebral disks to rupture. However, vets often recommend maintaining a healthy weight. Prescription diets such as Hill’s Metabolic or Hill's r/d may be used for this purpose.

We hope this article has given you insight into this intimidating disease. Thank you for reading, and please don’t hesitate to contact your regular veterinarian if you have specific queries about your pet.