Syringomyelia is the second most important inherited disease of the Cavalier King Charles Spaniel, right after mitral valve disease. Unlike the heart, this is a neurological condition that cannot be heard with a stethoscope or found on an ordinary examination, but only by magnetic resonance imaging.
The name sounds daunting and the subject is often passed over in silence. This article explains what actually happens in the spinal cord, how common the disease is, how it is recognised and what a breeder can do to reduce the risk.
What syringomyelia is
Syringomyelia is a condition in which fluid-filled cavities form within the spinal cord. These cavities press on the nerve fibres that carry the sensation of touch and pain, so the dog feels discomfort, tingling or pain in places where there is no injury at all.
In Cavaliers the cause is almost never an injury, but the shape of the skull. That brings us to the second term always mentioned alongside syringomyelia.
Chiari-like malformation — the cause behind the cause
In Cavaliers the back part of the skull is too small for the brain inside it. The cerebellum therefore presses against the opening at the base of the skull through which the spinal cord passes. This shape of skull is called Chiari-like malformation.
The result is disturbed flow of cerebrospinal fluid at the junction between head and neck. When the fluid cannot flow freely, pressure drives it into the spinal cord where it creates cavities. This is how Chiari-like malformation leads to syringomyelia.
It is important to keep the two apart: Chiari-like malformation is a shape of skull and is found in almost every Cavalier, while only some of them develop syringomyelia. A finding of Chiari-like malformation on its own is therefore not a reason for alarm.
How common the disease is
Data from the large screening programmes in the Netherlands and Denmark give the most reliable picture. Syringomyelia was found in about 39 percent of the Cavaliers scanned, with a clear link to age: the older the dog, the higher the likelihood.
More recent estimates range widely, between 25 and 70 percent, depending on the population and the age of the dogs scanned. What all the studies agree on is that the risk rises with every year of life.
There is one more thing worth knowing. Not every dog with cavities on the scan has symptoms. Some dogs with syringomyelia never show any signs and live normally, while in others the disease significantly affects quality of life.
Signs to watch for
In Cavaliers symptoms most often appear between six months and three years of age, though they can come later. The most characteristic signs are:
- scratching at the neck and shoulder in which the paw does not touch the skin, often while walking or when the dog is excited
- intermittent neck pain, seen as a stiffly held head
- sudden yelping with no visible cause, especially at night or when getting up
- oversensitivity to touch around the neck, ears and shoulders
- reluctance to jump, run up stairs or lower the head to the bowl
- in more severe cases weakness of the legs or curvature of the spine
Phantom scratching is the most recognisable sign and the most common reason an owner first seeks out a vet. It is not proof in itself, however: the same behaviour can be caused by allergy, fleas or an ear problem, so those causes are always ruled out first.
Diagnosis: why an MRI is needed
Syringomyelia cannot be confirmed by a blood test, an X-ray or an ultrasound. The only reliable method is magnetic resonance imaging, performed under anaesthesia and covering the head and the neck part of the spine.
The result is graded on an internationally accepted scale, separately for the shape of the skull and for the cavities:
- Chiari grade 0: no malformation.
- Chiari grade 1: the cerebellum is indented but does not pass through the opening of the skull.
- Chiari grade 2: the cerebellum is pressed into the opening or passes through it.
- Syringomyelia grade 0: a normal result.
- Syringomyelia grade 1: widening of the central canal narrower than 2 millimetres.
- Syringomyelia grade 2: a cavity of 2 millimetres or wider, or a separate cavity within the spinal cord.
The dog's age at the time of the scan is recorded alongside the grade, because a clear result in a young dog does not rule out the disease appearing later.
Treatment
Syringomyelia is in most cases managed with medication, the aim being to control pain and reduce the production of cerebrospinal fluid. The drugs most often used are those that calm nerve pain, together with anti-inflammatory medicines when needed.
Surgery is considered only in dogs for whom medication does not help. The procedure widens the space at the base of the skull and eases the flow of fluid, but it does not remove cavities that have already formed and does not guarantee a permanent solution.
For dogs with mild complaints it is often enough to adapt daily life: a harness instead of a collar, the food bowl raised to chest height, avoiding sudden jumps and a calm environment.
What a responsible breeder does
Unlike the heart, there is no examination here that can be done in any practice. An MRI is expensive and requires anaesthesia, so it is carried out by breeders who take the breed seriously.
The recommendations of the specialist programmes are as follows:
- the minimum age for scanning is twelve months, but a result is worth far more if the dog is scanned at three years or later
- the greatest value lies in a scan of a dog older than five years, because the result then also covers late onset of the disease
- at least one parent in the pair should be free of syringomyelia
- mating two dogs with confirmed syringomyelia is not recommended under any circumstances
The Dutch screening programme showed that this produces a measurable result: the share of affected offspring fell from about 38 percent to about 27 percent over a period of several years.
What to ask the breeder
The questions follow the same logic as for the heart, they simply relate to a different examination:
- Have the parents had an MRI, and at what age?
- What grade is written in the report, separately for Chiari-like malformation and for syringomyelia?
- May I see the report and the images?
An answer that the breed “does not have that problem” is not true and is the best sign that you should keep looking. Chiari-like malformation is present in practically every Cavalier and is spoken about openly, and it is precisely that openness that separates a breeder from a dealer.
Conclusion
Syringomyelia is a serious disease, but it does not affect every Cavalier and does not automatically mean a poor life. What an owner can do is choose a puppy from a litter whose parents have been scanned, recognise the early signs and go to the vet in time instead of putting the scratching down to habit. A great deal can be achieved with medication for the pain, and an early examination saves both dog and owner years of uncertainty.
Note: this article is informational and does not replace examination and advice from a veterinarian. For diagnosis and treatment consult your vet, preferably a specialist in neurology.
Related
- Mitral valve disease (MVD) in Cavaliers: stages, signs and treatment
- Heart murmur in Cavaliers: what it means and when it is a cause for concern
- Why Cavaliers scratch their neck and shoulder — when it is a sign of illness
- Which health tests are required for the parents of a Cavalier litter
- The expected lifespan of the Cavalier and what affects it
- A schedule of veterinary check-ups by the age of a Cavalier
- Eye problems in Cavaliers: what occurs and how to recognise it
- Patellar luxation in Cavaliers: the slipping kneecap of small breeds
- Ear problems in Cavaliers — why drop ears need more care
- How to read a Cavalier cardiology report
- MRI screening for syringomyelia: when, how and what the report means
- Cavalier vaccination and deworming: schedule by age
- Living with a Cavalier diagnosed with MVD
- Health of the Cavalier King Charles Spaniel — an overview of all topics
- Puppies for sale from a kennel with health-tested parents
