Birds are very good at hiding illness. Tests are used in conjunction with the findings of a physical examination and presenting history in order to diagnose an illness.
Syringomyelia is the term that describes fluid-filled cavities that develop within the spinal cord causing abnormal sensation in affected dogs. The underlying issue is called chiari-like malformation (CLM). CLM describes a mismatch between the size of the brain, which is too big, and the space within the skull, which is too small. Dogs that develop CLM and subsequent syringomyelia will often develop withdrawn behavior.