The Scottish Fold is a distinctive breed of domestic cat characterised by a natural dominant gene mutation associated with osteochondrodysplasia.

This genetic anomaly affects cartilage throughout the body, causing the ears to "fold", bending forward and down towards the front of the head.

This condition causes the ear fold as well as malformed bone structures, and the breed can develop severe painful degenerative joint diseases at an early age.

The original Scottish Fold was a white barn cat named Susie, who was found at a farm near Coupar Angus in Tayside, Scotland, in 1961.

When Susie had kittens, two of them were born with folded ears, and one was acquired by William Ross and his wife, Molly, neighbouring farmers who were cat fanciers.

However by the early 1970s the GCCF stopped registering the cat due to concerns about potential health issues such as ear infections and deafness.

In 1970 the first Scottish Fold kittens were introduced to America via a Dr. Neil Todd of Massachusetts who was researching the mutation.

[5] The International Cat Association (TICA) was the first registry to recognized the longhairs for championship competition in the 1987-88 show season and CFA followed in 1993-94.

There is suspicion that some non-fold litters are genetically heterozygous folds but because of very low expression of the gene, appear to be straight-eared.

[13] Legal bans on the breeding and sometimes sale of Folds have been enacted in several countries, including Australia, Austria, Belgium, Netherlands, Norway, and Scotland, due to the breed's health issues, especially deformities and pain caused by osteochondrodysplasia, which results in abnormalities in bone and cartilage throughout the body.

[21] Because of its health problems, the breed is not accepted by either the Governing Council of the Cat Fancy[22][23] or the Fédération Internationale Féline (FIFe).

[24][25] GCCF withdrew registrations in 1971 due to crippling deformity of the limbs and tail in some cats and concerns about genetic difficulties and ear problems such as infection, mites, and deafness, but the Folds were exported to the Americas and the breed continued to be established, using outcrossing with British Shorthairs and American Shorthairs.

[1] In the FIFe discussion, the representative for British breeders claimed that they were not seeing the problem in their cats, and that the study which showed that all heterozygous also have the condition had a small sample size.

An offer of free X-ray radiography was presented to 300 breeders to find a Fold cat with healthy hind legs, but it was never taken up.

[29] Scottish folds are also popular among celebrities, one of them being American singer Taylor Swift, who owns two Scottish fold cats named Meredith Grey (after the titular character of the medical drama series Grey's Anatomy), and Olivia Benson (after the protagonist of the police drama series Law & Order: Special Victims Unit).

[32] A study in Japan found two genes linked to hypertrophic cardiomyopathy in the Scottish Fold population.

Each reviewer gave on average the folded ear cats a worse "severity score", however the images showed much milder signs than previously published.

In a 2020 case study,[36] two Scottish Fold mixed cats with severe exostosis in the hind leg are described.

In a large retrospective Australian study [38] over 30,000 patient records from veterinary clinics were searched for specific keywords to look for the occurrence of OCD in Scottish Fold cats.