CONDITION
Syringomyelia
Why this matters now
Syringomyelia is a condition where fluid-filled cavities (syrinxes) develop within the spinal cord. In dogs, it most commonly occurs secondary to Chiari-like malformation, a skull abnormality that obstructs normal fluid flow at the base of the brain. Cavalier King Charles Spaniels are particularly affected, with studies suggesting over half may have some degree of the condition. Griffon Bruxellois and other toy breeds also show increased prevalence. Signs can range from absent to severely debilitating.
The condition typically develops progressively, though the rate varies considerably between individuals. Many dogs with imaging evidence of syringomyelia remain asymptomatic throughout their lives. When signs do develop, they often begin with intermittent episodes of scratching or discomfort, particularly around the neck and shoulders. Some dogs progress to more persistent pain and neurological deficits, whilst others remain stable for extended periods. The relationship between syrinx size and clinical signs is not straightforward.
Signals & patterns
Early signals
Phantom scratching
A distinctive behaviour where the dog scratches at the air near the ear or neck without making contact with the skin, often whilst walking.
Sensitivity around the neck
Reluctance to have the collar touched or discomfort when the neck area is handled.
Intermittent yelping or crying
Sudden vocalisations that seem unprovoked may indicate nerve-related pain.
Head rubbing
Frequent rubbing of the face or head against surfaces or with paws.
Later signals
Persistent scratching behaviour
Phantom scratching becomes more frequent or occurs during various activities.
Weakness in limbs
Progressive neurological dysfunction may cause unsteadiness or weakness.
Scoliosis
Curvature of the spine can develop secondary to asymmetric muscle function.
Sleep disturbance
Difficulty settling or frequent waking may reflect ongoing discomfort.
Click to read about the biological mechanisms
How this is usually investigated
Diagnosis relies on advanced imaging, as clinical signs alone can mimic other conditions. MRI provides definitive information about both the skull abnormality and spinal cord changes.
Neurological examination
MRI scan
Cardiac assessment
CSF analysis
Options & trade-offs
Management ranges from monitoring asymptomatic dogs to medical or surgical intervention for those with clinical signs. Treatment aims to control pain and, where possible, address the underlying obstruction.
Monitoring
Regular assessment without active treatment for dogs without clinical signs.
Trade-offs: Appropriate for asymptomatic dogs. MRI changes do not necessarily mean treatment is needed. Regular check-ups help detect any progression.
Pain medication
Various analgesics to manage neuropathic pain.
Trade-offs: Often the first line approach for symptomatic dogs. May include gabapentin, pregabalin, or other medications. Effectiveness varies between individuals.
Medications to reduce CSF production
Drugs that decrease cerebrospinal fluid volume.
Trade-offs: May reduce pressure within the syrinx. Cimetidine and omeprazole have been used. Response is variable.
Corticosteroids
Anti-inflammatory medications to reduce swelling and discomfort.
Trade-offs: Can provide symptomatic relief. Long-term use carries side effects. Often used in combination with other treatments.
Surgical decompression
Surgery to enlarge the opening at the back of the skull and relieve obstruction.
Trade-offs: Aims to restore normal CSF flow. Can improve signs in many dogs. Outcomes vary and some dogs require revision surgery. Specialist procedure.
Common misconceptions
"All Cavaliers with syringomyelia need treatment"
Many dogs have MRI evidence of syringomyelia but no clinical signs. Treatment is based on symptoms, not scan findings alone. Asymptomatic dogs can often be monitored.
"Phantom scratching is just a habit"
This distinctive behaviour is strongly associated with syringomyelia in susceptible breeds. It appears to result from abnormal nerve sensations rather than itching or behavioural causes.
"Surgery cures syringomyelia"
Surgery aims to improve CSF flow and reduce symptoms. Many dogs improve, but the condition is managed rather than cured. Some dogs require ongoing medical management after surgery.
Observing any scratching behaviour, noting when it occurs and what seems to trigger it, provides valuable information. Being aware that Cavaliers and related breeds have higher risk helps prompt appropriate investigation of relevant signs. Understanding that severity varies widely supports informed discussions about individual prognosis. Recognising that treatment decisions depend on clinical signs rather than imaging alone helps set realistic expectations.
Last reviewed: 24 April 2026 · Dr Alastair Greenway MRCVS