Syringomyelia in Cavalier King Charles Spaniels

Syringomyelia in Cavalier King Charles Spaniels

By Dr. Ed Mapes
Stonebridge Animal Hospital
McKinney, Tx

We’ve had a real upsurge in the numbers of Cavalier King Charles spaniels of late – that’s great news for our practice because these are fantastic little dogs. Seeing more of these guys though prompts me to discuss a very serious condition for which this breed is predisposed: syringomyelia is a disorder that all owners of the King Charles must be aware.

Syringomyelia occurs because the skull does not fully enclose a part of the brain called the cerebellum. This causes portions of the brain stem to protrude through an opening of the skull (foramen magnum). The constriction impairs the normal flow of cerebrospinal fluid (CSF) from the brain to the spinal cord.

Affected dogs will paw and scratch at the back of their neck and shoulders as discomfort begins to manifest early in the course of the disorder. As the CSF backs up, pain becomes the main problem. Dogs become lethargic, resist movement, and yelp as discomfort increases.

Affected dogs prefer to arch their necks backward to control pain. They become agitated, cannot eat or sleep, and constantly seek to relieve the discomfort. Damage to spinal nerves finally affects the legs, which become progressively weaker. Paralysis can result when nerve transmission is cut off entirely.

Symptoms are not usually seen in puppies, but emerge as the skull reaches full size and cannot accommodate the brainstem. Symptoms begin to arise when the cerebellum first emerges through the foramen magnum and CSF flow is interrupted.

These patients are usually presented because of the pawing and scratching at the neck and shoulder areas without symptoms of skin problems. Before concluding a diagnosis of syringomyelia, though, I always do a thorough ear examination because another condition seen in the breed, secretory otitis media, can mimic the early signs.

In this disorder, a thick, mucous accumulation fills the middle ear of dogs, building pressure within that forces the tympanic membrane (ear drum) to bulge. We can see this with an otoscope. Resulting irritation and discomfort causes dogs to paw at the ear and neck regions.

One discriminating sign between the two conditions, though, is that they’ll shake their heads with otitis, which is not usually seen in syringomyelia because of the pain. Having ruled out secretory otitis media, definitive diagnosis of syringomyelia is best accomplished by a neurology specialist with access to CT scan or MRI.

Treatment options are categorized as either supportive and palliative or definitive. Palliative therapy includes medications to control pain and to decrease production of CSF. These may be helpful or even lend control of the problem in dogs with partial obstruction of CSF flow, but medical therapy alone cannot control symptoms in more severe cases.

Definitive therapy involves surgeries that increase the foramen magnum size or provide shunting for CSF to limit pressure. Surgery is most effective when performed relatively early in the disease process before nerve damage is done and the protruding cerebellum is intact.

Owners of Cavalier King Charles spaniels should be knowledgeable of this disorder in their dogs and seek veterinary help whenever signs begin to emerge. Breeders must accept responsibility for breeding only dogs without this disorder, since it is known to become more serious in successive breedings of known carriers.

Comments are closed.