what are the symptoms of the second?
mild discomfort to severe pain and partial paralysis.
Cavalier King Charles Spaniel
Syringomyelia (SM) is a condition affecting the brain and spine, causing symptoms ranging from mild discomfort to severe pain and partial paralysis. 
how big does a king charles cavalier get Historically the Cavalier King Charles Spaniel was a lap dog and is small for a spaniel, with fully grown adults comparable in size to adolescents of other larger spaniel breeds. did this species diverge from some other group? Yes - spaniel can you please describe this species? A type of gun dog with a long silky coat and drooping ears, broad muzzle. The prevailing color is liver and white, sometimes red and white or black and white, and sometimes deep brown, or black on the face and breast, with a tan spot over each eye. are they popular? Yes - The Cavalier King Charles Spaniel has grown in popularity in the United States and ranks as the 19th most popular pure-breed in the United States. how is their behavior? highly affectionate, playful, extremely patient and eager to please. can you mention any common disease/ailments that they suffer from? Mitral valve disease, syringomyelia, hip dysplasia
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Cavalier King Charles Spaniel [SEP] Syringomyelia
Syringomyelia (SM) is a condition affecting the brain and spine, causing symptoms ranging from mild discomfort to severe pain and partial paralysis. It is caused by a malformation, commonly known as Chiari Malformation, in the lower back of the skull which reduces the space available to the brain, compressing it and often forcing it out (herniating it) through the opening into the spinal cord. This blocks the flow of cerebral spinal fluid (CSF) around the brain and spine and increases the fluid's pressure, creating turbulence which in turn is believed to create fluid pockets, or syrinxes (hence the term syringomyelia), in the spinal cord.