Cervical Disc Disease

Canine Cervical Disc Disease

You are petting your dog for something he or she did that was good and your dog yelps out in pain for no good reason. Your pet just stands there with a stiff neck, afraid to move. When it turns its head it seems to be in a huge amount of discomfort. We could be looking at a dog with cervical disc disease.
 

stiff neck and painful

A more common term for cervical disc disease is a ‘slipped disc’ in the neck. The discs are the structures between the bones of the spine (vertebrae) that act as shock absorbers. As in people, discs in dogs degenerate as they get older.
 

This process results in the discs becoming dehydrated and losing their cushioning effect. They may then ‘slip’ in one of two ways. Firstly, the material in the center of the disc can come out of the fibrous ring and injure the spinal cord. Secondly, the fibrous ring may thicken and compress the spinal cord. Either type of ‘slipped disc’ may cause neck pain and nerve injury.

The Clinical Signs:

Neck pain
Signs of neck pain may be obvious e.g. yelping and crying or rigidity of the neck. More subtle signs include reluctance to jump or climb and low head carriage. Difficulty lowering the head to eat from the floor may be evident.

 

The Diagnosis

A neurological examination is necessary to detect evidence of spinal cord injury and neck pain. There are many other causes of neck pain and nerve injury in addition to cervical disc disease. As a result investigations are necessary to confirm a ‘slipped disc’ and exclude these other conditions.

Normal survey X-rays of the neck under sedation or anesthesia may reveal evidence of cervical disc disease, such as a narrowed disc space or a calcified disc. However, more advanced

closed space between c2-3

investigations are necessary to see which disc has actually slipped and to assess the severity of any spinal cord compression. Of these advanced imaging techniques, an MRI scan provides the best method of investigating cervical disc disease. Instead of X-rays, MRI uses high powered magnets and a computer to generate images of the spine. MRI provides information not only on the health and position of the discs in the neck but also on the nature of any injury to the spinal cord. This makes diagnosis more accurate and assists greatly in deciding the best course of treatment for the individual patient.

Myelography is another imaging technique which can be used for investigating cervical disc disease. This involves injecting a dye (contrast agent) around the spinal cord and obtaining multiple X-rays to assess the flow of the dye to see if it is interrupted at the site of the slipped disc. Injecting around the spinal cord is not without risk of causing further damage to already compromised nerve tissue. MRI is less invasive than myelography with less risk of side-effects, and for most patients MRI provides the best option for investigation. Both MRI and myelography require the dog to have a general anesthetic

Occasionally it is necessary to collect some fluid (cerebrospinal fluid - CSF) from the spine and send it to a laboratory for analysis. This test assists in the diagnosis of inflammatory conditions that affect the spine.

The Treatment

The two principle methods of managing cervical disc disease are (1) conservative treatment and (2) surgery.

1. Conservative treatment
   When dogs with cervical disc disease are managed conservatively their exercise must be restricted. Short walks on a harness for toileting purposes may be necessary, with strict confinement at other times. The hope is that the ‘slipped disc’ will heal, any neck pain subside and the spinal cord recover from any injury. Painkillers may be necessary and possibly other drugs such as muscle relaxants.
    
2. Surgery
   The aims of surgery are to remove any disc material that is compressing the spinal cord and to prevent any more disc material ‘slipping’. Decompressive surgery involves removing a section of bone from the bottom of the spine (ventral slot) to enable retrieval of disc material. Further
   
   ‘slipping’ is prevented by removing any remaining material in the center of the disc (disc fenestration). Occasionally vertebral stabilization (fusion) procedures are necessary, especially in large dogs.

The Prognosis

The outlook or prognosis with cervical disc disease is generally good.

Conservative management can be successful in cases with neck pain and no evidence of spinal cord injury, such as weakness and incoordination. Unfortunately some dogs continue to deteriorate with this approach or recover only to have a recurrence weeks or months later.

The success rate with surgery is generally high provided that the spinal cord hasn’t been compressed for a long time (chronic spinal cord injury). Chronic cord injuries can be treated successfully with surgery, but the outlook is less favorable than it is for short-term (acute) injuries.

The Providence Veterinary Hospital Blog is a publication of Peter Herman, VMD, at the Providence Veterinary Hospital, 2400 Providence Ave. in Chester, PA. Contact Dr. Herman at 610-872-4000 or visit us at http://www.providencevet.com. 

Some information was obtained from Willows Veterinary Centre and Referral Service in the UK

 

 

 

 

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