Chiari-like malformation (CM) the most common cause of foramen magnum obstruction and syringomyelia in dogs. Syringomyelia (SM) is a disease of the spinal cord typified by fluid filled cavities, or syrinxes, within the spinal cord substance but it can cause pain by disrupting the cerebrospinal fluid (CSF), in the brain [1] CM is a condition characterized by the mismatch of size between the brain and the skull.[2][3] CM is very widespread in many Toy breed dogs and has been studied in the Cavalier King Charles Spaniel and the Griffon Bruxellois (Brussels Griffon) and Chihuahua.[4] As many as 95% of Cavalier King Charles Spaniels may have CM.[5] It is worldwide in scope and not limited to any country, breeding line, or kennel, and experts report that it is believed to be inherited [6] CM is so widespread in the Cavalier that it may be an inherent part of the CKCS's breed standard.[7] This disease not only affects thousands of dogs, but a similar condition affects over three hundred thousand children yearly.[8] Therefore, canines are an appropriate model for the treatment of the human condition.[8]
^Loughin CA (March 2016). "Chiari-like Malformation". The Veterinary Clinics of North America. Small Animal Practice. 46 (2): 231–42. doi:10.1016/j.cvsm.2015.10.002. PMID26631589.