By Marcy Speer
ASAP Research Committee Chair


The Cavalier King Charles Spaniel has a high rate of Chiari type I malformation, and it has been documented to be transmitted in a genetic fashion. Approximately 200,000 Americans (about 1/1500) are affected with the Chiari type I malformation, which manifests itself with symptoms similar to that observed in the Cavalier King Charles Spaniel, including chronic unremitting pain and the need for neurosurgical intervention. At least a subset of patients affected with Chiari type I malformation have it because of a genetic condition as well. Genetic studies are on-going in humans, but these may be slow and complex. The comprehensive and complete pedigree structure describing the Cavalier King Charles Spaniel population may provide a unique and valuable resource to further genetic studies in both species. 

Since dogs and humans are 85% similar at the level of DNA sequence, a gene that leads to Chiari type I malformation in dogs may cause the same problem in humans; similarly, if a gene is found to cause Chiari type I malformation in humans, it may very well be the same genetic culprit that causes the condition in dogs. Thus, these genetic studies should proceed in parallel, capitalizing on the unique characteristics of each species, and sharing information to maximize the success of each approach. Thus continues the long history of dogs as mans best friend, and in this case, man may demonstrate himself to be dogs best friend as well.