What is syringomyelia?
Syringomyelia refers to an accumulation of cerebrospinal fluid (CSF) in several cavities of the spinal cord causing compression of the latter and progressive atrophy of its nerve fibers. When the cavity forms in the brain, it is called hydromyelia.
What is CSF?
Cerebrospinal fluid (CSF), also commonly called cerebrospinal fluid, is a clear liquid that bathes the central nervous system consisting of the brain and spinal cord. This liquid absorbs shocks and evacuates certain metabolic waste products.
Syringomyelia in dogs: the various possible causes
In dogs, syringomyelia is linked to an obstruction of the normal flow of cerebrospinal fluid due to:
- the presence of a mass in the brain or within the spinal cord,
- of an inflammatory phenomenon,
- trauma.
But, most often, syringomyelia finds its origin in the presence of a congenital occipital malformation. It is a malformation of the posterior part of the skull which consists of a narrowing of the orifice where the cerebellum and the cervical part of the spinal cord communicate, thus preventing the CSF from flowing normally. This malformation, also called "Chiari's disease" , particularly affects dogs of brachycephalic breeds (dogs with a short skull and a crushed nose) such as the Cavalier King Charles, the Pug, the Pekingese, the Shih Tzu or the French Bulldog.Some small dogs like the Yorkshire, the Westie or even the Bichon Frisé would also be predisposed to it.
Syringomyelia symptoms in dogs
The formation of a cavity in the spinal cord is at the origin of the appearance of various clinical signs including:
- a cervico-facial pruritus: the dog feels intense itching/pain between his shoulders, in his neck, in his ears which pushes him to adopt frantic scratching behavior,
- from time to time a deviation of the neck or even pain in the cervical level,
- sometimes dizziness, ataxia or even lameness or weakness of the front limbs and more rarely of the hindquarters.
The appearance of these symptoms generally occurs between the dog's 6 months and 3 years of age, although it remains possible throughout the life of the animal.
How is syringomyelia detected?
Faced with clinical signs suggestive of syringomelia, the veterinarian will perform a neurological examination and use magnetic resonance imaging (MRI) to confirm his diagnosis.
Possible treatments
Treatment for syringomyelia may consist of:
- a medical treatment whose objective is:
- first to relieve the dog's pain by administering analgesic and/or anti-inflammatory drugs,
- then to help drain the CSF or reduce its production by administering diuretics or proton pump inhibitors.
- a surgical treatment that aims to expand the animal's occiput to decompress the spinal cord and raise the flow of CSF at this level.
Prognosis depends on the severity of symptoms and the dog's response to treatment.While the majority of dogs see their symptoms diminish with treatment (with the exception of scratching, which seems to persist in most cases) or even completely resolve, some may nevertheless respond poorly and suffer from a degraded quality of life.