What can we do about this problem?
In the consultation we will aim to acquire two main types of information. First we will grade your pet’s injury using the above scale. Second we will localise the injury by performing clinical tests that assess reflexes and the areas affected by the injury. Whilst all of your dog’s discs will be equally degenerate, most of the problems associated with this relates to the discs in the middle of the back between the chest and the lumbar spine. By testing your dog’s reflexes we will be able to identify the general area of the problem. By listening to your pet’s history and considering your pet’s breed and age we will be able to give some indication of whether the problem is likely to be due to disc problems or some other disease process. In other words, at the end of the consult we will be in a position to make an educated guess as to the location, severity and likely cause of the problem. In most cases this guess is not good enough to direct treatment however and therefore further investigations will be offered. The normal investigations for a spinal patient are as follows:
- Plain survey radiographs: This is X-rays of your dog’s spinal column. This procedure will give us some information about the back bones, the size of the disc space between them and the health of the gel centre. This will help in many cases to rule out certain causes of spinal problems but will not often give a diagnosis. For this reason we will often perform:
- Myelography: The spinal cord is made of soft tissue and thus does not appear on the plain X- rays. When we perform Myelography we inject a dye that outlines the spinal cord and allows us to see whether it is swollen or compressed (squeezed by the disc material). We will also be able to determine where the compression is in the spinal column and whether it is greater on one side than the other. This procedure therefore will confirm the suspected diagnosis of disc extrusion and allow us to correlate the clinical signs from the consultation with the image on the X-ray.
- CSF Examination: Sometimes we will collect the fluid from around the spinal cord (cerebrospinal fluid or CSF) and submit this to a laboratory.
Following these tests, we will know the cause of the spinal problem and its exact location. If we see that the cord is being squeezed or compressed by the hardened gel, then we will likely recommend surgical management.
Why is surgery necessary?
If the centre of the disc was still soft and gel like then all of the problems your pet is experiencing would be due to the bruising of the cord alone and as with other bruises this will resolve of its own accord without surgery. If someone has a snowball thrown at them, a bruise may develop but there is no evidence of the cause of the bruise because the snowball was soft and broke up on impact. However if someone is shot, then a bruise will develop and the presence of the bullet may cause further injury if left in place. In most chondrodystrophoid breeds, the injury is much more like being shot than being hit by a snowball because the gel has turned into a hardened mass, the presence of which in the spinal canal will squeeze the cord and cause further injury, resulting often in a poorer recovery from spinal injury. In these cases we suggest ‘decompressive surgery’. In this surgery we make a little window into the spinal canal and remove this hardened material thus relieving the spinal cord of compression. After this has been performed, the bruise will still be present in the spinal cord at the point of impact and this will have to resolve in order for your dog to recover from the injury, however this is much more likely to happen smoothly and progressively once the material has been removed than if it was left in place. The other advantage of surgery is that as well as taking the disc material out of the spinal canal, we will also remove any residual hardened gel from the centre of the problem disc and this will reduce the likelihood of problems with this disc in the future. Disc patients treated non-surgically will often have a recurrence of back problems at the same site. In most cases we will also remove the centre of the disc in front and behind the problem disc. This can often reduce the likelihood of your pet experiencing back problems in the future to that seen in other breeds (very low). In summary surgical management has four goals:
- To reduce the pressure on the spinal cord.
- To prevent problems associated with this disc again in the future.
- To prevent problems associated with the discs surrounding the problem disc.
- To permit active physiotherapy earlier in the course of recovery. In patients treated non- surgically there is a risk of further material moving into the spinal canal after the initial injury. Non surgical cases with compression are therefore confined strictly for 6 or more weeks after the incident, whilst surgically managed cases do not face this risk and can be active as soon as they are ready (within limits of course).