CM / SM in Cavaliers: Chiari-like Malformation and Syringomyelia
CM / SM: Chiari-like Malformation and Syringomyelia
Cavalier’s brains are too large for their skull.
Cavalier’s skull does not allow the brain enough space. The brain is crowded and pushed on by the skull. The cute “stop”, looked at as a “forehead” in Cavaliers is pushing their brain backwards into the back of their skull. Their brain should be shaped like a football, but is sadly shaped like a basketball.
This skull shape is the reason Cavaliers are plagued with the painful conditions of CM / SM: Chiari-like Malformation and Syringomyelia.
Brachycephaly is caused by the premature fusion of skull bones, which can lead to a range of problems, including:
– A shortened muzzle
– A rounded head
– A flattened face
– Impaired brain fluid flow (SM)
The skull shape changes associated with brachycephaly can impair the flow of Cerebrospinal Fluid (CSF), a clear fluid that surrounds the brain and spinal cord. This can lead to a range of problems, including:
– Impaired waste removal
– Increased pressure in the brain (CM)
– Spinal cord problems (SM)
Cerebrospinal Fluid (CSF) flows through the brain and spinal cord, removing waste and excess fluids. It also helps to cushion the brain and spinal cord from injury.
Cavalier King Charles Spaniels are prone to CSF-related conditions due to their skull shape and structure. This is why Cavaliers have such a high incidence of Chiari-like Malformation and Syringomyelia.
Population data shows that MOST Cavaliers are affected with CM, and over half of all Cavaliers are affected with SM. This means the breed is in PAIN. These two related conditions are man-made. Humans are at fault for creating dogs with high risk of extreme pain. Humans can also choose to change Cavaliers’ heads to remedy this high-risk painful condition. Dog breeders are in charge of how they choose to breed the look, structure and morphology of dogs.
The leading expert on the subject is Dr Clare Rusbridge
** pictures are from Dr Clare Rusbridge’s data
Breeding Strategy
Cavaliers should mainly be paired with “other breeds” that do not have any CM/ SM: Chiari-like Malformation and Syringomyelia in their breed. This is easily done since we know what breeds and head shapes are commonly affected with painful CM / SM. All dogs with Brachycephalic head traits are commonly at ‘risk’. Dogs with longer skulls and without any Brachycephalic traits are not on the list of types of dogs with CM / SM.
The answer is very clear. Cavaliers need a completely changed head shape.
The goal should be a cute spaniel head type, that has zero Brachycephalic head traits. To achieve this, dogs need to have a sloped stop, not a high forehead with a sharp stop.
The future Cavaliers-blended dogs from our project should end up with a more moderate head that shows no Brachycephalic traits. This means the future of Cavaliers can be pain free.
Dr Clare Rusbridge is Professor in Veterinary Neurology at University of Surrey and Senior Neurologist at Wear Referrals. Her experience with painful and distressing inherited and conformation related disease drives her research to improve diagnose, treatment and prevention of these conditions. She has spent over 25 years researching Chiari malformation, syringomyelia and neuropathic pain and has authored or co-authored over 160 scientific articles and book chapters including a textbook on human syringomyelia. She is a trustee for the Dog Breeding Reform Group
