Causes
Malformation or instability of the neck vertebrae that compresses the spinal cord. There is a genetic component. Large and giant breeds are the ones affected.
Diagnosis
A neurological examination plus an MRI scan to see the compression.
Treatment
Mild cases: rest, pain control, a suitable collar/harness. Moderate to severe cases: surgery to decompress the spinal cord. Physiotherapy helps with recovery.
Prevention
Do not breed from affected animals. A correct diet during the growth of large breeds.

