Polydactylism is extremly common in Nova Scotia. It is a genetic mutation where a cat can have one or more extra toes. My sister's female cat has 7 toes on her front feet, and 6 on the back, and her male cat has 6 in front and 5 in back.
Apparantly there was a family of cats somewhere in the distant past of Nova Scotia that had extra toes, and they spread all across the province. There are literally thousands of cats with polydactylism in Nova Scotia now because several cats had it in the past.