The Royal (Dick) School of Veterinary Studies
Royal Dick School of Veterinary Studies Bicentenary

Specialist surgery increases size of spaniel skull

Veterinary specialists and researchers collaborate to relieve pain in Cavalier King Charles Spaniels.

A Cavalier King Charles Spaniel has made a long-term recovery following a complex operation to enlarge the capacity of her skull.

Ruby, who was aged two and a half at the time of her treatment, was born with a painful, life-threatening disease in which fluid gathers in the spinal cord.

A neurosurgeon from the Dick Vet led the treatment for the condition, which is thought to be caused by an odd conformation of the skull. This condition, called Chiari-like malformation, is estimated to affect as affect as many as 99 per cent of Cavalier King Charles Spaniels.

Signs of disease

Model of Cavalier King Charles Spaniel skull.
Ruby's skull was recreated in 3D from image scans.

Ruby’s owner became aware of her condition when the dog exhibited signs of severe pain and phantom scratching – making scratching motions without touching the skin – around her ears, neck and shoulder.

An MRI scan at the Hospital for Small Animals confirmed that Ruby had chronic syringomyelia – a slow accumulation of fluid within the spinal cord, caused by the Chiari like malformation. This is estimated to affect up to 70 per cent of Cavalier King Charles spaniels by six years of age.

Ruby’s condition was already very advanced, with the fluid occupying approximately two-thirds of her spinal cord.

Vets created an extension to the skull, tailored to Ruby’s measurements, in a specialist procedure using titanium mesh and bone cement.

Due to the complex, precise nature of the surgery, techniques such as 3D prints of the patient’s skull are used, allowing vets to plan precisely and ensure an optimum long-term outcome.

Long-term progress

Ruby's condition was caused by a malformation.

Six years following surgery, Ruby has had no episodes of severe pain, and her condition has not progressed. 

Ruby receives painkillers to control intermittent phantom scratching, but no additional treatment has been needed.

Ruby’s care was led by vet neurosurgeon Katia Marioni-Henry, one of the few specialists in the UK who can carry out such operations.

HfSA vets in neurology, dermatology and pathology are collaborating on another condition common in Cavalier King Charles spaniels, called middle ear effusions (MEE) or primary secretory otitis media (PSOM), which shares some clinical signs with Chiari-like malformation.

Middle ear effusion may cause impaired hearing, facial paralysis, loss of balance, head tilt, and itchy ears, together with head and neck pain as reported for Chiari-like malformation and syringomyelia.

Effusions were found to be associated with neurological deficits in more than one-third of dogs, and skin and ear inflammations in more than half of affected dogs.

Fluid accumulation in the middle ear is similar to the condition of glue ear common in children, and insights from the disease in dogs may be valuable for managing the disease in animals and people.

Their study describing the benefits of understanding the condition in Cavalier King Charles Spaniels is published in the Journal of Veterinary Medicine.

In Ruby’s case, surgical procedures managed to stop the clock in progress of the disease. This condition should eventually be eliminated from the breed with screening and careful breeding, but in the meantime, surgical treatment seems to be a valid option for dogs presenting signs of syringomyelia at a relatively young age and with pain that does not respond to treatment. This study highlights the need for a holistic approach to the treatment of pain in Cavalier King Charles Spaniel. We were very fortunate to be able to collaborate with other specialists at the HfSA to give Ruby, and other lovely Spaniels, the best possible care.

Katia Marioni-HenrySenior Lecturer in Vet Neurology, Hospital for Small Animals

Related links

Neurology and Neurosurgery at the Hospital for Small Animals

Specialist publication in Journal of Veterinary Medicine

Kennel Club guidance on Chiari-like malformation