Scottish Fold
Lilac coloured adult Scottish Fold, displaying round face, round eyes and forward-folded ears
Other namesScot Fold
Origin Scotland
Breed standards
CFAstandard
TICAstandard
WCFstandard
ACFA/CAAstandard
Notes
Not recognised by FIFe and GCCF
Domestic cat (Felis catus)

The Scottish Fold is a distinctive breed of domestic cat characterised by a natural dominant gene mutation associated with osteochondrodysplasia. This genetic anomaly impacts cartilage throughout the body, causing the ears to "fold", bending forward and down towards the front of the head. While this trait contributes to the breed's unique appearance, often described as "owl-like",[1] it is essential to note that osteochondrodysplasia can have negative effects on the cats' welfare.

Originally called lop-eared or lops after the lop-eared rabbit, Scottish Fold became the breed's name in 1966.[1] Depending on registries, longhaired Scottish Folds are varyingly known as Highland Fold, Scottish Fold Longhair, Longhair Fold and Coupari.

All Fold cats are affected by osteochondrodysplasia, a developmental abnormality that affects cartilage and bone development throughout the body. This condition causes the ear fold in the breed and studies point to all Fold cats being affected by it. Fold cats therefore have malformed bone structures and can develop severe painful degenerative joint diseases at an early age.[2] Due to these health conditions, breeding Fold cats is prohibited in several countries and some major cat registries do not recognise the cat breed.

History

Origin

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. 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 was acquired by William Ross, a neighbouring farmer and cat-fancier.[3] The breeding programme 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.[4]Ross registered the breed with the Governing Council of the Cat Fancy (GCCF) in the United Kingdom in 1966 and started to breed Scottish Fold kittens with the help of geneticist Pat Turner. 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. Further cats were brought over and the Scottish Fold breeding program continued with American Shorthairs and British Shorthairs being introduced.[5]

Breed recognition

In 1978 the Cat Fanciers' Association (CFA) granted the breed championship status. In the mid 1980s the long-haired version started to gain recognition.[5]

Characteristics

Scottish Fold longhair kitten

Ears

Scottish Fold with straight ears

Scottish Fold kittens that do not develop folded ears are known as Scottish Straights.[1]

The breed's distinctive folded ears are produced by an incompletely dominant gene that affects the cartilage of the ears, causing the ears to fold forward and downward, giving a cap-like appearance to the head. Smaller, tightly folded ears set in a cap-like fashion are preferred to a loose fold and larger ear. The large, round eyes and rounded head, cheeks, and whisker pads add to the overall rounded appearance. Despite the folded ears, folds still use their aural appendages to express themselves—the ears swivel to listen, lie back in anger and prick up when the treat bag rustles.[5]

Body

The Scottish Fold is a medium to large sized cat, which can come in any colour, even calico. Males typically weigh 4–6 kg (8.8–13.2 lb), and females weigh 2.7–4 kg (6.0–8.8 lb). The Fold's entire body structure, especially the head and face, is generally rounded, and the eyes large and round. The nose is short with a gentle curve, and the cat's body is well-rounded with a padded look and medium-to-short legs. The head is domed at the top, and the neck very short. The broadly-spaced eyes give the Scottish Fold a "sweet expression".[4]

Coat

A Scottish fold kitten

Scottish Folds can be either long- or short-haired, and they may have nearly any coat colour or combination of colours (including white).[4] Shorthair Scottish Folds have thick and soft fur, with longhair Folds having longer fur and tufts located around the extremities.[6]

Genetics

An early study suggested that the fold is inherited as an autosomal dominant trait.[7] A later study suggested an incomplete dominance.[8] A cat with folded ears may have either one (heterozygous) or two copies (homozygous) of the dominant fold gene (Fd). A cat with normal ears should have two copies of the normal gene (fd).

Homozygous fold
Fd Fd
Homozygous fold Fd Fd Fd Fd Fd
Fd Fd Fd Fd Fd
Heterozygous fold
Fd fd
Homozygous fold Fd Fd Fd Fd fd
Fd Fd Fd fd Fd
Straight-eared
fd fd
Homozygous fold Fd Fd fd Fd fd
Fd Fd fd Fd fd

Mating a homozygous fold with any cat will produce all folds, but because homozygous folds are prone to severe health issues, breeding for them is generally considered unethical. A homozygous to normal mating will produce only heterozygous folds but presumably in ethical breeding programs, there will be no homozygous cats available to breed from.

Straight-eared
fd fd
Heterozygous fold Fd Fd fd Fd fd
fd fd fd fd fd

The only generally accepted breeding gives a 50% chance of producing heterozygous folds and 50% chance of producing progeny with normal genes.

Heterozygous fold
Fd fd
Heterozygous fold Fd Fd Fd Fd fd
fd fd Fd fd fd

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. Such kittens may develop folded ears initially which then straighten back out. Because of this there are suggestions by some breeders to avoid mating Folds with straight-eared Scottish Folds but only use British Shorthairs (BSH) as outcross.[9][10] If Scottish Shorthairs are to be used, they should be test mated to a BSH to make sure that they are not genetically folds.[9] If such apparent straight-eared cats are mated with a fold, there is a 75% chance of folds (25% homozygous folds, 50% heterozygous folds) and 25% chance of straight ears.

In 2016, the genetic mutation responsible for the folded ears and the osteochondrodysplasia was identified. It was found in a gene encoding a calcium permeable ion channel, transient receptor potential cation channel, subfamily V, member 4 (TRPV4).[11] The mutation is a V342F substitution (c.1024G>T) in the fifth ankyrin repeat within the N-terminal cytoplasmic domain. It was also found in a human patient with metatropic dysplasia.[12]

Acceptance

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. Some of the major cat registries, such as the GCCF and FIFe, do not recognise, nor allow for the registry and competition showing of, Scottish folds.

Legal bans

Due to the prevalence of osteochondrodysplasia in the breed (see below), several countries and states have prohibited breeding with Scottish folds, in order to protect animal welfare. Banning countries include the Netherlands in 2014,[13] Austria in 2020,[14][15] Flanders (Belgium) in 2021,[16] Victoria (Australia),[17] Norway in 2023,[18] and even the birthplace of the breed, Scotland.[19][20] The breed is also indirectly banned by Swedish legislation prohibiting the breeding of animals with genetic make up that makes it likely to produce unhealthy offspring.[21] Some countries have also banned selling[16] of Scottish fold cats, or the breeding with any cat that bears the gene mutation resulting in osteochondrodysplasia, so even breeding with some of the Scottish straights may be legally restricted.[13] Potential parent cats can be tested for this mutation before breeding.[22]

Registry bans

Because of its health problems, the breed is not accepted by either the Governing Council of the Cat Fancy[23][24] or the Fédération Internationale Féline (FIFe). [25][26] 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. Since the initial concerns were brought, the Fold breed has not had the mite and infection problems.[1]

Cat Fanciers' Association breeders have stated that using only fold to non-fold breeding has eliminated problems with stiff tails, shortened tails, and bone lesions.[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.[27][28] A similar offer was set up by the World Cat Federation together with researcher Leslie Lyons but there was also no response. FIFe stated that they will not consider recognizing Scottish Folds if breeders will not allow their breed to be scrutinized.[29]

In a report on Scottish Folds, the Breed Standards Advisory Council for New Zealand Cat Fancy (NZCF) states that "Breeders may not have appreciated the strength of the evidence that heterozygous cats can and do develop [feline] OCD." While research shows that all heterozygous Folds develop OCD, and anecdotal evidence shows that heterozygous Folds can and do develop OCD, they do not show whether mildly affected parents are more likely to have mildly affected offspring. They also do not show what percentage of Folds are severely affected. The report states that there is not enough information to justify banning Scottish Fold matings, but enough to justify a level of concern.[9] Recommended guidelines include:

Popularity

Despite warnings from organisation such as GCCF ("we strongly advise members of the public not to try to acquire cats of this breed"[24]), the distinctive physical traits of the Scottish Fold, combined with their reputation as unusually loving companions, make Folds highly sought-after pets, with Fold kittens typically costing considerably more than kittens of more common breeds.[30] 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).[31]

Health

The medical problem most associated with the breed is osteochondrodysplasia, which leads painful malformed bones and joint diseases, especially when both parents were of the folded-ear form, as covered in detail below.

Scottish folds are also susceptible to feline polycystic kidney disease (PKD).[32] A study in Japan of cats suspected to have kidney problems found that 54% of tested Scottish Fold cats had the PKD1 mutation, which is responsible for PKD.[33]

Scottish folds are also prone to cardiomyopathy (disorders that affects the heart muscle)'[34] and degenerative joint disease (a type of arthritis), most commonly affecting the tail, ankles, and knees which can result in reduced range of motion.[6] Wax buildup in the ears may be greater than in other cats.[1]

Osteochondrodysplasia

Osteochondrodysplasia (OCD) is a developmental abnormality that affects cartilage and bone development throughout the body. This condition causes the ear fold in the breed and, in studies conducted so far, all Fold cats are affected by it.[2] Homozygous Folds are affected by malformed bone structures and develop severe painful degenerative joint diseases at an early age. Some breeders claim that this condition also affects heterozygous Folds, but usually to a much lesser extent and at a later age.

In a 2021 study,[35] four radiologists, blinded to the ear phenotype, assessed radiographs of 22 Scottish Fold/Straight cats. All cats were genotyped showing the heterozygous mutation in all folded ear cats but not in straight cats. Each reviewer gave on average the folded ear cats a worse "severity score", however the images showed much milder signs than previously published. The authors state that the severity of OCD in heterozygous cats is very variable and subtle. This could be due to other modifier genes or nurture (climate, diet, exercise). So it was shown that the least affected folded ear cat was given identical or less score than the highest rated straight ear cat.

In a 2020 case study,[36] two Scottish Fold mixed cats with severe exostosis in the hind leg are described. Both cats were homozygous for the TrpV4 mutation, assuming the parental cats had both the c.1024G>T mutation in the TrpV4 gene. This reinforces the hypothesis that mostly homozygous Scottish Folds are severely affected.[37] On the other hand it is concerning that still Scottish Fold cats are bred with each other, also breeding with other cat strains with skeletal abnormalities (Munchkin, American Curl) should be avoided.

While ethical breeders breed fold/non-fold and not fold/fold (in the same way Munchkins and Manx are bred – one parent having the trait and one not) to avoid producing homozygous Folds,[4] because heterozygous Folds can also develop progressive arthritis of varying severity, some researchers recommend abandoning the breeding of Fold cats entirely.[7][38]

The Cat Who Went to Paris

The short novel The Cat Who Went to Paris by Peter Gethers features "the most famous Scottish Fold" according to Grace Sutton of The Cat Fanciers' Association.[1] The book documents the life of Gethers and his Fold, Norton, from their first meeting to Norton's eventual death and Gethers' experiences after the loss.

See also

References

  1. ^ a b c d e f g Sutton, Grace (31 May 1999). "Breed article: Scottish Folds". Cat Fanciers' Association. Archived from the original on 29 April 2019. Retrieved 29 January 2012.
  2. ^ a b "Genetic welfare problems of companion animals: Scottish Fold: Osteochondrodysplasia". Universities Federation for Animal Welfare. 2011. Archived from the original on 19 March 2012. Retrieved 2 February 2012.
  3. ^ "Scottish Fold Brochure" (PDF). Cat Fanciers' Association. Retrieved 22 January 2024.
  4. ^ a b c d "Scottish Fold FAQ". Fanciers.com. Retrieved 3 October 2009.
  5. ^ a b c "Scottish Fold history". Pegkens Scottish Folds. Retrieved 22 January 2024.
  6. ^ a b "Scottish Fold Cat Breed Information, Pictures, Characteristics & Facts." CatTime, https://cattime.com/cat-breeds/scottish-fold-cats#/slide/1. Accessed 26 September 2017.
  7. ^ a b Malik, R.; Allan, G. S.; Howlett, C. R.; Thompson, D. E.; James, G.; McWhirter, C.; Kendall, K. (February 1999). "Osteochondrodysplasia in Scottish Fold cats". Australian Veterinary Journal. Vol. 77, no. 2. pp. 85–92. PMID 10078353.
  8. ^ Takanosu, M.; Takanosu, T.; Suzuki, H.; Suzuki, K. (April 2008). "Incomplete dominant osteochondrodysplasia in heterozygous Scottish Fold cats". The Journal of Small Animal Practice. 49 (4): 197–9. doi:10.1111/j.1748-5827.2008.00561.x. PMID 18339089.
  9. ^ a b c "Minutes of Executive Council Meeting No: 28 (doc)". New Zealand Cat Fancy. 24–25 September 2011. Retrieved 3 February 2012.
  10. ^ Sutton, Grace. "Breed Article: Scottish Folds". cfa.org. Cat Fanciers' Association. Retrieved 7 December 2013.
  11. ^ Gandolfi, B.; Alamri, S.; Darby, W. G.; Adhikari, B.; Lattimer, J. C.; Malik, R.; Wade, C. M.; Lyons, L. A.; Cheng, J.; Bateman, J. F.; McIntyre, P.; Lamandé, S. R.; Haase, B. (2016). "A dominant TRPV4 variant underlies osteochondrodysplasia in Scottish fold cats". Osteoarthritis and Cartilage. 24 (8): 1441–1450. doi:10.1016/j.joca.2016.03.019. PMID 27063440.
  12. ^ Dai, J.; Kim, O. H.; Cho, T. J.; Schmidt-Rimpler, M.; Tonoki, H.; Takikawa, K.; Haga, N.; Miyoshi, K.; Kitoh, H.; Yoo, W. J.; Choi, I. H.; Song, H. R.; Jin, D. K.; Kim, H. T.; Kamasaki, H.; Bianchi, P.; Grigelioniene, G.; Nampoothiri, S.; Minagawa, M.; Miyagawa, S. I.; Fukao, T.; Marcelis, C.; Jansweijer, M. C.; Hennekam, R. C.; Bedeschi, F.; Mustonen, A.; Jiang, Q.; Ohashi, H.; Furuichi, T.; Unger, S. (2010). "Novel and recurrent TRPV4 mutations and their association with distinct phenotypes within the TRPV4 dysplasia family" (PDF). Journal of Medical Genetics. 47 (10): 704–709. doi:10.1136/jmg.2009.075358. PMID 20577006. S2CID 925054.
  13. ^ a b "Fokken met katten - Honden en katten". NVWA.nl (in Dutch). Netherlands Food and Consumer Product Safety Authority. 31 October 2022. Retrieved 1 April 2023.
  14. ^ "Qualzucht bei Katzen". Tieranwalt.at (in German). Tierschutzombudsstelle Wien. Retrieved 1 April 2023.
  15. ^ "RIS - Tierschutzgesetz - Bundesrecht konsolidiert, Fassung vom 01.04.2023". RIS.BKA.gv.at. Retrieved 1 April 2023.
  16. ^ a b "Verbod op de kweek en het verhandelen van fold katten". Vlaanderen.be (in Dutch). Retrieved 1 April 2023.
  17. ^ "Code of Practice for the Breeding of Animals with Heritable Defects that Cause Disease". Agriculture Victoria. Victoria Department of Jobs, Precincts and Regions. 6 July 2020. Retrieved 1 April 2023.
  18. ^ Løkkevik, Ole (4 July 2023). "Mattilsynet: Avl på katterasen Scottish Fold er i strid med dyrevelferdsloven". VG (in Norwegian). Retrieved 4 July 2023.
  19. ^ Schofield, Claire (2019). "Scottish fold cats: why the adorable breed is banned in Scotland but is huge in the US and Japan". The Scotsman.
  20. ^ "Question reference: S5W-15391". Parliament.scot. The Scottish Parliament. 2018. Retrieved 1 April 2023.
  21. ^ "xtreme breeding in Europe - Mapping of legislation" (PDF). Eurogroup for Animals. Retrieved 22 January 2024.
  22. ^ "Scottish Fold". vgl.ucdavis.edu. Veterinary Genetics Laboratory, University of California, Davis. Retrieved 1 April 2023.
  23. ^ "Cat Breeds not recognised by GCCF but with some recognition by WCC members" (PDF). GCCFCats.org. Governing Council of the Cat Fancy. 2021.
  24. ^ a b "The GCCF says Health Comes First". GCCFCats.org. Governing Council of the Cat Fancy. Archived from the original on 4 May 2015.
  25. ^ "Breed standards". FIFeWeb.org. Fédération Internationale Féline. 2023. Retrieved 1 April 2023.
  26. ^ "Breeding and Registration Rules". FIFeWeb.org. Fédération Internationale Féline. 1 January 2008. §2.7.3 "Genetic Diseases". Archived from the original on 20 August 2008.
  27. ^ "FIFe decision not to accept Scottish Fold breed in May 2003". Retrieved 2 February 2012.
  28. ^ "Email from ScottishFoldandScottishShorthairGroup". 2008. Archived from the original on 1 July 2012. Retrieved 2 February 2012.
  29. ^ "Minutes of the Business Meeting of the World Cat Congress: Arnhem, the Netherlands: 14th April. 2009". Retrieved 2 February 2012.
  30. ^ "Choosing a Scottish Fold". Pet Place. Retrieved 3 October 2009.
  31. ^ Dailey, Hannah. "Taylor Swift's Cat Olivia Benson Is Reportedly Worth $97 Million". Billboard. Penske Media Corporation. Retrieved 31 January 2023.
  32. ^ Little, Shirley. "Polycystic Kidney Disease (PKD)". ScottishFold.org. Retrieved 3 October 2009.
  33. ^ Sato, R.; Uchida, N.; Kawana, Y.; Tozuka, M.; Kobayashi, S.; Hanyu, N.; Konno, Y.; Iguchi, Aiko; Yamasaki, Yayoi; Kuramochi, Konomi; Yamasaki, Masahiro (2019). "Epidemiological evaluation of cats associated with feline polycystic kidney disease caused by the feline PKD1 genetic mutation in Japan". The Journal of Veterinary Medical Science. 81 (7): 1006–1011. doi:10.1292/jvms.18-0309. PMC 6656814. PMID 31155548.
  34. ^ Little, Shirley. "Cardiomyopathy". ScottishFold.org. Retrieved 3 October 2009.
  35. ^ Rorden, Chris; Griswold, Marilee C.; Moses, Nan; Berry, Clifford R.; Keller, G. Gregory; Rivas, Rudy; Flores-Smith, Helen; Shaffer, Lisa G.; Malik, Richard (2021). "Radiographical Survey of Osteochondrodysplasia in Scottish Fold Cats caused by the TRPV4 gene variant". Human Genetics. 140 (11): 1525–1534. doi:10.1007/s00439-021-02337-5. PMID 34406467. S2CID 237198301.
  36. ^ Takanosu, Masamine; Hattori, Yuki (2020). "Osteochondrodysplasia in Scottish Fold cross-breed cats". The Journal of Veterinary Medical Science. 82 (12): 1769–1772. doi:10.1292/jvms.20-0299. PMC 7804039. PMID 33162427.
  37. ^ Takanosu, M.; Takanosu, T.; Suzuki, H.; Suzuki, K. (2008). "Incomplete dominant osteochondrodysplasia in heterozygous Scottish Fold cats". The Journal of Small Animal Practice. 49 (4): 197–199. doi:10.1111/j.1748-5827.2008.00561.x. PMID 18339089.
  38. ^ Malik, Richard (2003). "Genetic Disorders of Cats". World Congress Proceedings, 2003. World Small Animal Veterinary Association. Retrieved 20 December 2009.

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