Osteochondrodysplasia is a disease that is unique to Scottish Folds. It was discovered that if a folded ear Scottish fold was bred to another folded ear, many of the offspring developed a severe crippling lameness early in life. It is a developmental abnormality that affects cartilage throughout the body. It is this that causes the abnormal ear shape in Scottish fold cats. Its effects in other parts of the body, especially the limb bones, are much more serious, causing severe distortion of limb bone shapes and severe arthritis. Cats affected had shortened, malformed legs and tail as well as abnormalities affecting the growth plates and spine. The disease can be apparent in animals as young as 7 weeks and persists throughout life. It causes crippling, lameness and serious chronic pain. There is no cure. As a result, the breed is outlawed by the Cat Fancy in the UK, the GCCF, and FIFe.
Research conducted in Australia in February 1999 suggests, for the first time, that even heterozygous Scottish Fold cats may also become afflicted with progressive arthritis. It suggested that cats homozygous for the Fold gene develop crippling arthritis at an early age and that heterozygous Folds also develop arthritis but more slowly. Indeed, this study suggests all Scottish folds with folded ears will eventually develop arthritis of various severity.
There are no carriers of the gene which are not themselves unaffected: all folded-eared cats develop osteochondrodysplasia to some extent. Cats with normal ears produced from the mating of a folded-eared cat to a non-folded eared cat are genetically fd/fd and do not have the mutated gene or the condition. These cats are called Scottish shorthairs and they do not have Osteochondrodysplasia.
We encourage pet owners to get Scottish Folds with single fold to minimise the chances of Osteochondrodysplasia.