The original Scottish Fold was a long-haired white-haired barn cat named Susie, who was found at a farm near Coupar Angus in Perthshire, Scotland in 1961. Susie's ears had an unusual fold in their middle, making her resemble an owl. When Susie had kittens, two of them were born with folded ears, and one of the siblings was acquired by William Ross, a neighbouring farmer and cat-fancier. Ross registered the breed with the Governing Council of the Cat Fancy in Great Britain and started to breed Scottish Fold kittens with the help of geneticist Pat Turner. The breeding program produced 76 kittens in the first three years - 42 with folded ears and 34 with straight ears. The conclusion from this was that the ear mutation is due to a simple dominant gene. If one parent with the gene for straight ears, and one parent with the gene for folded ears, the kittens will be folds.
The breed was not accepted for showing in Great Britain and Europe as it was felt that they would be extremely prone to ear problems such as infection, mites and deafness, but the folds were exported to America and the breed continued to be established there using crosses with British Shorthair cat and the American Shorthair cat.
Scottish Folds can be either long or short-haired, and they may have any coat colour combination except for Siamese-style points. Pointed Folds have been bred but they are not eligible for showing. The original cats only had one fold in their ears, but due to selective breeding they have increased the fold to a double or triple crease that lies the ear totally flat against the head.
There is one medical problem that has been found to be related to Scottish-Fold breeding. If both parents have folded ears, their kittens will be extremely prone to developing a painful degenerative joint disease that fuses the tail, ankles and knees. The disease is not fatal, but as it is easily avoidable, reputable breeders will only breed fold to non-fold.