Chiari Malformation & Syringomyelia
Some Maltese breeders are breeding for the more brachycephalic or baby doll type head.
In doing so, breeders may be inadvertently encouraging a skull that is too small for the back part of the brain, resulting in a condition known as Chiari malformation (CM). It is also known as Caudal Occipital Malformation Syndrome (COMS).
One of the consequences of this skull type is that the back of the skull can form abnormally small and lead to part of the brain called the cerebellum, being forced into the spinal cord. If the cerebellum protrudes into the spinal cord, it interrupts the flow of cerebral spinal fluid (CSF).
The CSF play a very important role as it surrounds and protects the brain and spinal cord, as well as provides nutrients and removes waste.
When the flow of CSF is compromised, it creates fluid filled cavities or cysts within the spinal cord. This condition is called Syringomyelia (SM).
CM and SM usually go hand in hand as a combined problem. If a dog has CM, it will inevitably have SM.
Both CM and SM are diagnosed by MRI.
Symptoms of CM/SM include:
-air or phantom scratching in mid-air while walking
-pain is the biggest issue and can range from mild to severe. The pain may come and go
-weakness in the limbs
-head rubbing or shaking; exaggerated and extensive yawning; digging
CM/SM can be insidious. Some puppies with CM/SM can have severe symptoms in early life with the head/neck pain being so excruciating that euthanasia is the only recourse. On the other end of the spectrum, some dogs can be asymptomatic and lead normal lives. Some dogs have mild to moderate CM/SM and respond well to corticosteroids or non-steroidal anti-inflammatory drugs (NSAIDS). Other newer medications can help ease the fluid pressure and pain associated with CM/SM.
In severe cases, the only option is surgery which does have a good success rate.
CM is considered an inherited problem. Obviously, affected dogs should never be bred from.
Maltese breeders may want to be cautious about breeding for Maltese with the very domed (high forehead) skull. The Maltese standard does call for a moderate head.
While CM/SM is not a common problem like it is in Cavalier King Charles Spaniels and Brussels Griffons, it isn't something we want to perpetuate in Maltese.