The canine population has during it?s time with humans gone through at least 2 major genetic bottlenecks, the first when it was separated from the wolf, and the second when it was divided into different breeds. Among other things, this has lead to the accumulation of unwanted genes, such as genes causing disease in dogs. One such inherited disease is Syringomyelia, which has proven to be more common than expected, especially in certain smaller breeds such as the Cavalier King Charles Spaniel. Syringomyelia in dogs is often a secondary condition caused by the malformation called occipital hypoplasia.