The cerebellum is the part of the brain that regulates the control and coordination of movement. With this condition, cells in the cerebellum mature normally before birth, but then deteriorate prematurely causing clinical signs associated with poor co-ordination and lack of balance. The Purkinje cells in the cerebellum are primarily involved; cells in other areas of the brain may also be affected.
CA has been seen in the Australian Kelpie, Gordon Setter, Border Collie, Labrador Retriever, Airedale, English Pointer, Scottish Terrier, Kerry Blue Terrier, Miniature Schnauzer, and other dog breeds. Time of onset varies. In a few breeds, such as the Beagle, Rough Collie, and Miniature Poodle, Purkinje cells begin to die off at or shortly before birth, and pups are born with symptoms or develop symptoms by three to four weeks of age. Most breeds prone to the condition, such as the Kerry Blue Terrier, Border Collie, Australian Kelpie, and Labrador Retriever, begin showing symptoms between six and sixteen weeks of age. In a very few breeds, such as the American Staffordshire Terrier, Old English Sheepdog, Brittany Spaniel, and Gordon Setter, symptoms do not appear until adulthood or even middle age.
In dogs, CA is also usually an autosomal recessive gene, but in a few breeds, such as the English Pointer, the gene is sex-linked.