Feline Chiari Malformations
Chiari malformations (also referred to as “Chiari-like malformations”) are a collection of highly heritable neurologic disorders that are believed to result from a variety of malformations of the occipital bone of the skull.
While our understanding is limited when it comes to knowing exactly how these diseases states arise, conformational deformities of the foramen magnum (the site through which the brainstem passes) and a subsequent crowding of the sensitive neurologic structures located here have been implicated.
Once considered rare, the increased popularity of Cavalier King Charles Spaniels dog, along with the increased availability of neurologic imaging techniques, has led us to deem the condition far more common than we formerly believed. Although rare, it’s been determined that cats can also be affected.
What to Watch For
The most common clinical sign initially observed in Chiari malformation patients is scratching at the neck or shoulders. As the condition progresses, loss of balance (ataxia), weakness, and neck pain may develop.
Diagnosis of Chiari Malformations in Cats
Age and symptoms are generally considered evidence for a presumptive diagnosis.
Definitive diagnosis, however, can only be achieved via MRI of the skull and neck.
Treatment of Chiari Malformations in Cats
Treatment of Chiari malformations is difficult for severely affected patients. For those more mildly affected, medical treatment with steroids (like prednisone) and/or gabapentin has proven somewhat effective – at least initially.
As the condition progresses, a procedure called foramen magnum decompression may be effective in relieving the pressure on the affected structures. Some patients may receive a lifelong reprieve from symptoms after undergoing this highly specialized procedure.
Veterinary Cost Associated with Chiari Malformations
Because definitive diagnosis requires a high tech imaging technique, the cost of diagnosis can be prohibitive for many pet owners. Typical costs for an MRI range anywhere from $1,000 to $2,000.
The cost of treatment depends greatly on the severity of the disease. If medical management is considered sufficient, expenses are likely to remain under $50 a month for the drugs most commonly employed in these cases.
Surgical management through foramen magnum decompression is considered expensive. Estimates ranging from $5,000 to $10,000 are common.