Fact Sheet Cat Breed Scottish Fold

 3. Problems/syndromes that may occur in the breed

The most important of several problems and possible diseases occurring in this breed are described here:

• Osteochondrodysplasia
• Brachycephaly
• Brachycephalic Obstructive Airway Syndrome (BOAS)
• Polycystic Kidney Disease (PKD)
• Ocular diseases (exophthalmos, entropion, corneal ulcers)

4. Other problems that may occur frequently

In addition to the breed-typical defects listed under point 3, the veterinary literature contains information on the occurrence of the following problems, which will not be discussed further below, as no definitive conclusions can yet be drawn from the known prevalences and breeders, breeding clubs and associations do not state any prevalences that have been determined under scientific conditions. However, the following statement applies to these cases: „The absence of evidence is not the evidence of absence“.

• Diseases of the respiratory tract
• Cardiovascular diseases
• Hypertrophic cardiomyopathy 
• Urolithiasis (calcium oxalate)
• Factor XII deficiency
• Progressive retinal atrophy

5. Symptoms and pathological value of the typical defects mentioned above: Significance/impact on the physical/psychological well-being of the defect in the individual animal and classification in burden category*

*The individual breeding-related defects are assigned to different burden categories (BC) depending on their severity. The overall burden category is based on the most severe defect found in the individual animal. The BC system as a further development based on the Swiss model is still being developed and is only intended as a guide. For this reason, the BC values used here should be regarded as provisional. This is primarily due to the fact that the German Animal Welfare Act does not contain a justiciable basis for classification into burden categories. In contrast to Switzerland, the legal standards in Germany do not quantify pain, suffering or harm or assess their quality, but take them into account if they affect the animal more than insignificantly.
However, the burden categories can also be used to assess suitability for breeding and showing.

The burdens that can be caused by defective breeding traits are divided into 4 categories (Art. 3 TSchZV, Switzerland). The most burdenful trait or symptom is decisive for the assignment of an animal to a burden category (Art. 4 TSchZV, Switzerland).

Category 0 (no burden): These animals may be used for breeding.

Category 1 (mild burden): Mild burden is present if a burdenful expression of characteristics and symptoms in pets and farm animals can be compensated for by appropriate care, husbandry or feeding, without interventions on the animal and without regular medical care measures.

Category 2 (medium burden): These animals may only be used for breeding if the breeding objective is for the offspring to be less burdened than the parents.

Category 3 (severe burden): These animals may not be used for breeding.

Osteochondrodysplasia (see also leaflet no. 3 Cat ears)

Physical:
The insufficient cartilage of the ears cannot hold the auricles in a physiological shape, so that they fold forward or tilt at the age of three to four weeks. The cartilage changes leading to the development of folded ears are caused by a generalized defective cartilage metabolism, which leads to further cartilage and bone damage and is referred to as osteochondrodysplasia of the Scottish fold (SFOCD).

A retrospective analysis of a database from Australia (VetCompass Australia) revealed that 12 out of 1,131 Scottish Folds were diagnosed with osteochondrodysplasia. The disease was suspected in a further 64 Scottish Folds. The authors of the study cite as possible reasons for the low prevalence that the search terms used did not capture all affected cats or that necessary information was not submitted to the database. In addition, data on individual cats may be incomplete, as not all clinics provide their data. This could have led to an underrepresentation.

The cats can show radiographic changes as early as seven weeks of age, with homozygous allele carriers being affected earlier than heterozygous allele carriers. Osteochondrodysplasia appears to occur as a result of defective enchondral ossification in the distal limbs, which is associated with the breeding-related cartilage defect. Both bone growth and articular cartilage formation are impaired. The cats show shortened limbs and malformations of the limbs as well as changes in the growth plates, which are visible radiographically.
The severity of the changes and symptoms can vary greatly. The affected cats show reluctance to move, an altered or abnormal and stiff gait, lameness, swelling in the hind limbs, kyphosis and sometimes clear signs of pain. The limbs (especially metacarpi and metatarsi) and also vertebral bodies (of the tail) can be shortened. The Scottish Fold can therefore appear small in stature. In severe cases, affected cats may also develop urinary and defecation problems as well as respiratory problems.

The changes in affected Scottish Folds may include bone deformities resulting from impaired bone growth and, as they progress, progressive ankylosing polyarthropathies (inflammation and stiffening of joints associated with arthritis) of the distal limbs and vertebral bodies (lumbar and caudal vertebrae). All limbs or only the hind limbs may be affected, although the hind limbs appear to be affected earlier and more frequently. The shortening of the extremities mainly affects the distal areas and the joints may show swelling.

The animals may react painfully to palpation of affected limb regions as well as to palpation of the tail region and may have problems moving the tail. The tail may also be shortened and thickened.  As the disease progresses, the changes in the bones and joints of the limbs progress and the sclerotic (compacted/hardened) areas and irregular bone structure increase. Bone formations can occur in the limbs and between the vertebrae.

It can be assumed that all homozygous allele carriers are severely affected by the disease. Heterozygous allele carriers are also affected, but to varying degrees. As a rule, homozygous animals develop symptoms earlier and with greater severity, while heterozygous animals show moderate or mild severity, but are nevertheless also affected. 

Bone formations are observed less frequently in heterozygous allele carriers and are more solitary than in homozygous allele carriers. In general, the disease appears to occur more slowly and be milder in heterozygous cats. The different clinical manifestations appear to be related to the fact that the mutation is inherited in an incompletely dominant manner.

Apart from purely palliative therapy with pain and anti-inflammatory medication, only invasive surgical interventions to alleviate symptoms (possibly also chondroprotective supplements (e.g. glucosaminoglycans, chondroitin sulphate)) can be considered. A case study from Switzerland investigated radiotherapy as an alternative. The follow-up results after 28 months were good and showed only minimal additional bone formation. Palliative radiotherapy can alleviate pain, but cannot stop the progression of the disease completely, and must also be considered on a case-by-case basis, as general anesthesia is required for each radiotherapy treatment. 

Psychological:
Even at a very young age, affected cats suffer from chronic pain due to arthritis. Typical behaviors such as climbing or jumping are impaired or even impossible. Their nature can be severely altered, so that they spend most of their time hiding and lying down. As osteochondrodysplasia cannot be cured, cats are affected for the rest of their lives. Cats communicate strongly through their ear and tail posture to communicate various states of excitement and emotions. The folded ears and an altered immobile tail impair this communication and thus severely restrict their species-typical behavior and social interactions with cats and humans. 

Burden category: 3

Brachycephaly  

(see also https://qualzucht-datenbank.eu/merkblatt-katze-brachycephalie/)

Physical:
The Scottish Fold belongs to the brachycephalic cat breeds. In her work, Schöll (2021) summarizes brachycephaly as an anatomical deformation of the facial skull. It is characterized by the shortening of the nose, the formation of a shoulder between the forehead and nose („stop“) and a flattened facial skull. This results in primary and secondary diseases and changes. Radiographic examinations of the skulls of Scottish Fold cats confirm that they have a very round head. The round head shape is associated with a shortened facial skull, which particularly affects the nasal region, and a shortened cranium.

As a brachycephalic breed, the shape of the skull has changed in comparison to mesocephalic breeds. The orbit is more caudal in the Scottish Fold than in other breeds. The narrowing of the nostrils and nasal entrance in combination with the kinked and narrow respiratory tract could be a risk factor for impaired thermoregulation.

In Gralla’s overview of eye diseases (2014), to which brachycephalic cats are predisposed, epiphora (leakage of tear fluid over the edge of the eyelid) is listed, which is associated with drainage disorders of the tear fluid. The altered brachycephalic skull anatomy results in a flat orbit with consequent exophthalmos, eyelids that are close to the eye and kinked nasolacrimal canals. The nasolacrimal canal is shorter and steeper in brachycephalic cats and has a right-angled to acute-angled course, whereas it is rostroventral in meso- and dolichocephalic cat breeds. In brachycephalic dog breeds, a reduced production of lacrimal fluid has been observed. A lower sensitivity of the cornea is assumed to be the cause. In contrast, a comparison of tear production in non-brachycephalic and brachycephalic cat breeds, including ten Scottish Folds, showed an increase in tear production in brachycephalic cats. The sensitivity of the cornea does not differ between brachycephalic and non-brachycephalic cat breeds.

Due to the lack of space in the brachycephalic skull, the teeth may be misaligned. The teeth of the upper and lower jaw may not lie on top of each other when closing the mouth (malocclusion) due to misalignment, which favors periodontal diseases. The position of the teeth differs greatly in brachycephalic cat breeds. The more pronounced the brachycephaly is, the more the teeth of the upper jaw tend to assume an increasingly horizontal position.

A retrospective analysis of skull CT scans examined for the first time morphological and morphometric differences of the bulla tympanica (part of the middle ear) in 15 non-brachycephalic and 11 brachycephalic cats, including 2 Scottish Folds. The study found that the bone of the bulla tympanica was significantly thicker in the brachycephalic breeds than in non-brachycephalic cats. Further studies in brachycephalic cats are needed to determine a possible association of a thickened bulla tympanica and otitis media with effusions.

Psychological:
The structural changes to the skull associated with brachycephaly severely restrict the affected cats in many areas of their lives: The malpositioned teeth can impair food intake. As a result, the animal can only fulfill this vital need with difficulty. The restricted thermoregulation impairs the cat’s well-being and active behavior. The altered facial expressions caused by the altered head shape are difficult for conspecifics to read and therefore lead to impaired communication within the species.

Burden category: 3

Brachycephalic obstructive airway syndrome (BOAS)

Physical:
As is known in brachycephalic cats e.g. Persians  (see QUEN leaflet no. 33), the breeding-related altered head shape can be associated with brachycephalic obstructive airway syndrome (BOAS). Most studies on the effects of brachycephaly and the associated BOAS have been carried out in dogs, although it can be assumed that it manifests similarly in cats. Although BOAS has not been widely studied in cats, it is thought to be common based on experience.

Reviews summarize the primary structural changes that can occur in brachycephalic obstructive airway syndrome: stenotic nostrils, an elongated soft palate, and a hypoplastic trachea. Although an elongated soft palate is less frequently documented in brachycephalic cats, it is unclear whether it is actually less common compared to dogs with BOAS or whether it is simply less frequently investigated or recognized. CT scans of brachycephalic cats (Persian cats) have shown that the turbinates are constricted and displaced into the airways due to the reduced space in the skull. This was also confirmed by endoscopic examinations of other brachycephalic cats. The resistance against which the animals have to breathe is increased due to the anatomical changes. Secondary symptoms may include everted (bulging) laryngeal pockets, oedematization of the larynx, laryngeal collapse, collapsed bronchi and gastrointestinal symptoms such as vomiting, oesophagitis and gastritis.

Upper airway obstruction affects breathing in brachycephalic cats and can also lead to obstructive sleep apnea. A survey of owners of cats, including 11 Scottish Folds, revealed that breathing problems and significant breathing noises are typical abnormalities of brachycephalic cats, which increase with the degree of brachycephaly. Clinically, the following symptoms are noticeable due to the brachycephalic changes: snoring breathing noises, mouth breathing, disruption of thermoregulation as well as reduced activity and additionally prolonged recovery phases. Cyanosis, retching, symptoms of the digestive tract and disturbed sleep behavior may also occur. The strained breathing also occurs during periods of rest and snoring breathing noises can also be heard when the animals are awake. The severity of clinical symptoms also depends on the extent of brachycephaly. In her summary, Schöll points out that mouth breathing in cats should always be regarded as severe respiratory distress that requires immediate therapeutic measures.

Psychological:
Respiratory distress is a major burden for affected cats and has a very negative impact on their well-being. It restricts them enormously in their active behavior. They need a longer recovery phase after active behavior. Food and water intake as existential behaviors can be impaired by respiratory distress. A survey of owners of brachycephalic and non-brachycephalic cats showed that brachycephalic cats behave less playfully and interactively. Poor sleep quality impairs the cats‘ necessary rest periods. The animals are therefore unable to fully meet their need for activity and rest.

Burden category: 3

Polycystic Kidney Disease (PKD)

Physical:
Polycystic kidney disease (PKD) is one of the most important hereditary diseases in cats due to its frequency. 

Scottish Fold cats are predisposed to the disease and the prevalence of the causative gene mutation in Scottish Fold cats is reported to be up to 54%, depending on the source.
In affected animals, the kidneys have congenital, bilateral cysts that grow over time and can eventually lead to chronic interstitial nephritis and kidney failure in middle-aged to older cats. These cysts often occur together with cysts in the liver and pancreas.

Symptoms of renal failure can vary widely and include anemic disease, painful and ulcerative inflammation of the mouth, vomiting, diarrhea, loss of appetite, cachexia, dehydration, pulmonary edema and metastatic calcifications in the pleura, gastric mucosa and lungs. Death usually occurs due to metabolic acidosis, increased potassium or calcium levels or final pulmonary edema.

Psychological:
Affected cats often suffer considerably from pain, suffering and damage. In advanced stages of the disease, euthanasia is often necessary for animal welfare reasons in order to prevent further suffering.

Burden category: 3

Ocular diseases  

Physical:
Brachycephalic breeds in particular, such as the Scottish Fold, are more frequently affected by ocular diseases. This is due to the skull changes associated with brachycephaly, which affect the orbit and the eyes themselves. In an analysis of clinical data from 2009 to 2021 from South Korea, the Scottish Fold was the third most common breed affected by ocular disease, accounting for 8.3%. The prevalence in the breed was 15%. In the Breed Report of the Swedish animal health insurance company AGRIA, the Scottish Fold also shows an increased relative risk of ocular disease compared to the other breeds. However, it should be noted that only a small number of Scottish Folds are insured with AGRIA and statements should therefore be assessed with caution.

Reduced corneal sensitivity can increase the risk of chronic keratitis, corneal ulceration and corneal sequestration (parts of the cornea become necrotic and pigment is deposited). In a comparison between 78 meso- and 62 brachycephalic cat breeds, it was found that corneal sensitivity is reduced in brachycephalic cats. In addition, corneal sensitivity decreases progressively with increasing degree of brachycephaly. The author suspects that the exophthalmos, which increases with increasing degree of brachycephaly, exposes the cornea to constant irritation and thus reduces corneal sensitivity. This increases the risk of corneal diseases. In their study, Oksa-Minalto et al. (2023), on the other hand, found no differences in altered corneal sensitivity between brachycephalic and non-brachycephalic cat breeds.

Entropion is an eyelid malposition in which the eyelid is turned inwards, causing the hairs of the eyelid to come into contact with the cornea. This can lead to irritation of the cornea and can be associated with conjunctivitis, blepharospasm (eyelid spasm), keratitis, corneal ulceration, corneal sequestration and trichiasis. Entropion occurs more frequently in brachycephalic cats such as the Scottish Fold. This is also confirmed by a study from Turkey with a total of 328 brachycephalic cats, including 53 Scottish Folds, in which the prevalence rate of this breed was 14.7 %. In another study from Turkey with a total of 649 cats that presented to the clinic with blepharospasm (eyelid spasm), entropion was diagnosed in 170 cats. 130 of these belonged to the brachycephalic group and the Scottish Fold breed was the second most commonly affected brachycephalic breed. In general, the risk of corneal necrosis is increased in entropion-associated corneal ulceration.

A retrospective analysis of data from a clinic in Turkey showed a higher prevalence of 19.4% for corneal ulceration in Scottish Folds compared to other brachycephalic breeds.

Psychological:
The respective ocular disease and its severity can lead to pain and suffering in the affected cats. Changes and (chronic) irritation of the cornea are very painful for the affected cats and are associated with suffering, as the cornea of cats is highly sensitively innervated. Entropion and any associated impairment of the eye are also associated with severe pain.

Burden category: 3

Conclusion

In the Scottish Fold, even the breed-related (standard-related) visible deviations in the anatomy of the ears can result in an overall category 3, because they are evidence of the defect present. Some of the cats from crosses with folded-eared cats have erect ears, such as the Scottish Straight. However, these cats can also carry the gene for osteochondrodysplasia and pass it on to their offspring. If this is suspected, genetic testing should be ordered.

Animal ethical evaluation of the problem of torture breeding in the Scottish Fold cat

Based on the facts stated in QUEN Fact Sheet No. 40, which lists the probability of a number of breeding-related defects in burden categories 2-3 (moderate to severe burden) and 3 (severe burden), it must be stated from an animal ethics perspective that continued breeding with affected animals of this breed is to be classified as highly problematic, as a breeder must assume that animals that he brings into the world through his breeding will have to endure or suffer considerable and continuous pain. This is already unacceptable if at least one of the breeding-related defects in burden categories 2-3 mentioned in this fact sheet occurs in a foreseeable manner in at least one of the animals bred by him, whereby „foreseeable“ hereditary changes in the offspring are also present if they are only expected to occur after a generation jump in later generations. 

6. Heredity, genetics, known gene tests, if applicable, average coefficient of inbreeding (COI), if applicable average heterozygosity value

Osteochondrodysplasia
The disease is caused by a point mutation in the TRPV4 gene. The c.1024G>T mutation was detected in the TRPV4 gene in all Scottish Fold cats with folded ears during genetic testing, which thus confirmed that this mutation is associated with folded ears. The mutation is inherited in an incomplete dominant manner. As already described in the conclusion under point 5, it is also possible that not all animals have the typical folded ears, but instead have normal ears, although these animals are also affected by osteochondrodysplasia and can pass it on. A copy of the underlying TRPV4 variant can also be detected in mongrel cats in which one parent was a Scottish Fold.

According to our current state of knowledge (2025), there is currently no method available to predict whether or not the offspring will develop a form of Scottish Fold osteochondrodysplasia based on the genotype. Breeding with a phenotypic Scottish Fold cat or trait-carrying designer cat should therefore be avoided at all costs. A genetic test is available.

Brachycephaly
In the 1999 Qualzuchtgutachten, the BMEL states the assumption that this is a polygenic hereditary mode with a threshold character and possible heterogeneity. In Persian cats, two candidate genes on chromosome A2, CNTN6 and CHL1, were identified in homozygous regions.

Polycystic Kidney Disease (PKD)
PKD is subject to autosomal dominant inheritance. The mutation affects the PKD-1 gene. A genetic test is available.

Other genetic tests available for the breed
– Progressive retinal atrophy (pd-PRA)
– Skeletal dysplasia
– Autoimmune lymphoproliferative syndrome (ALPS)

7. Diagnosis – further examinations

A general clinical examination and medical history are of course the starting point for any further diagnostics.

Osteochondrodysplasia
Radiological examinations, such as X-ray or MRI scans of the musculoskeletal system, are used for more precise assessment and visualization of osteochondrodysplastic regions (tarsal, carpal, metatarsal, metacarpal bones and phalanges). Histopathological examinations of the proliferated bone tissue can confirm the suspected diagnosis in a differential diagnosis in conjunction with the presented breed, medical history and existing clinical and radiological examination results. Indirectly, a suspected diagnosis can be supported by an improvement in the general condition after administration of a non-steroidal anti-inflammatory drug (diagnostic therapy) or dietary supplement to support the cartilage. A genetic test can be carried out to confirm the diagnosis.

Brachycephaly and brachycephalic obstructive airway syndrome (BOAS)
Anatomical abnormalities, such as stenotic nostrils, can be examined by means of adspection. Under sedation or anesthesia, the oral cavity and larynx can be examined more closely using endoscopy or a rhinoscopy can be performed. A CT scan of the skull provides further information on the changes present. X-ray examinations of the thorax illustrate possible changes in the trachea, lungs and diaphragm. Endoscopic examination of the upper airways in particular is necessary in order to be able to assess the structures better than is possible through adspection alone. The Jones test is suitable for checking the patency of the nasolacrimal canal. Schöll recommends a scheme according to Schlueter et al. (2009) for assessing the severity of brachycephalic disease and quality of life. This involves assigning the individual cat to a brachycephaly grade (grade I – mild to grade IV – severe) based on the anatomical changes and clinical signs present.

Polycystic Kidney Disease (PKD)
Polycystic kidney disease can be diagnosed by means of an ultrasound examination of the abdomen, imaging procedures such as CT or MRI and blood tests. A genetic test is also possible, but usually plays a subordinate role if clinical symptoms are already present.

Ocular diseases
A complete ophthalmologic examination should be performed, including Schirmer tear test, tonometry, ophthalmoscopy and other diagnostic procedures. The Jones test can be performed to examine the nasolacrimal canal. A genetic test for progressive retinal atrophy can be carried out.

8. Necessary or possible orders from an animal welfare perspective

Decisions on breeding or exhibition bans should be made in connection with the burden category (BC). Depending on the severity and findings, the decisive factor for a breeding ban may be the most severe finding, i.e. the finding that most affects the animal, and its categorisation in one of the burden categories (BC), or also the correlation assessment if many individual breeding-related defects or breed-typical predispositions are present. The individual genomic inbreeding coefficient of an animal and its status as a carrier animal for risk genes should also be taken into account. 

a) Orders that appear necessary

Breeding ban according to § 11b TierSchG for animals with hereditary/breeding-related defects, in particular for all cats with characteristic ear changes and for all animals with defects of burden category 3.

Exhibition ban at least for all animals with visible defect characteristics such as pronounced brachycephaly, in particular folded ears (as an externally visible sign of the genetic defect).

b) Possible orders

• Order for permanent sterilization (castration) in accordance with  11b (2) TierSchG. Note: Only surgical castration (ovariohysterectomy for female cats) is to be used as an animal welfare measure because drug therapy is unreliable and has side effects if used long-term.
• Order to carry out genetic tests on both partners intended for breeding

Please note:

Measures taken by the competent authority must be recognizably suitable for averting future harm to the animal concerned and/or its offspring. With regard to the type and depth of processing of orders and breeding bans, decisions are always made on a case-by-case basis at the discretion of the competent authority, taking into account the circumstances found on site.

9. General assessment of animal welfare law

a) Germany

From an animal welfare point of view, cats with the defects/syndromes described above are classified as torture breeding in Germany in accordance with §11b TierSchG.

The prohibition in Section 11b TierSchG applies not only if animals are used for breeding that themselves exhibit traits that are relevant to torture breeding, i.e. are carriers of traits (= diseased animals), but also if it is known or must be known that an animal used for breeding can pass on traits that can lead to one of the detrimental changes in the offspring. i.e. they are carriers without being affected themselves (see Hirt/Maisack/Moritz/Felde TierSchG 4th ed. § 11b para. 6 with reference to Binder; see also Lorz/Metzger TierSchG 7th ed. § 11b para. 14 with reference to BT-Drs. 13/7015, 22; BT-Drs. 17/10572, 31). This also corresponds to the intention of the legislature, which already aimed to comprehensively prevent torture breeding with the amendment in the 13th legislative period (BT-Drs. 13/7015, 22: extension of purely physical defects to behavioral disorders and possible consequences when attempting to correct them). These requirements are followed by case law with regard to carriers (see VG Schleswig-Holstein, judgment of 02.07.18 – 1 A 52.16 para. 85; VG Dresden, decision of 20.12.21 – 6 L 646.20 – p. 18, white Doberman, albinism) and the legislative intention to comprehensively prevent torturous breeding (VG Berlin judgment of 23.09.15 – 24 K 202.14 with annotation by Kröner et al. – beck-online, ZUR 2016, 181, 183; VG Hamburg, decision of 04.04.18 – 11 E 1067.18 para. 56). 

 – An important indication of a hereditary defect is that a disease or behavioral abnormality occurs more frequently in related animals than in the population as a whole The fact that the breed or population has proven to be viable over a longer period of time is not an argument against damage (cf. Lorz/Metzger § 11b para. 12).

 – The prohibition applies regardless of the subjective facts, i.e. regardless of whether the breeder himself recognized or should have recognized the possibility of harmful consequences (Lorz/Metzger § 11b para. 4). Due to this objective standard of care, the breeder cannot invoke a lack of subjective knowledge or experience if the respective knowledge and experience can be expected from a careful breeder of the respective animal species. 

– Hereditary changes in the offspring are foreseeable even if it is uncertain whether they will only occur in later generations after a generation jump (see Goetschel in Kluge § 11b para. 14; see also Lorz/Metzger TierSchG 7th ed. 2019 § 11b para. 14).

Justification:

According to §11b TierSchG, it is prohibited to breed vertebrate animals if breeding knowledge indicates that, as a result of breeding, the offspring or progeny will, among other things

• body parts or organs are missing for species-appropriate use or are unfit or deformed for hereditary reasons, resulting in pain, suffering or damage (§ 11b Para. 1 No. 1 TierSchG) or
• hereditary behavioral disorders associated with suffering occur (§ 11b para. 1 no. 2 a) TierSchG) or
• the keeping is only possible with pain or avoidable suffering or leads to damage (§ 11b Para. 1 No. 2 c) TierSchG).

Pain is defined in animals as an unpleasant sensory perception caused by actual or potential injury, which triggers motor or vegetative reactions, results in learned avoidance behaviour and can potentially change specific behaviours (Hirt/Maisack/Moritz/Felde, TierSchG, Kommentar 4th ed. 2023 § 1 para. 12 mwN; basically also Lorz/Metzger TierSchG 7th ed. § 1 para. 20).

Suffering is any impairment of well-being not already covered by the concept of pain that goes beyond simple discomfort and lasts for a not insignificant period of time (Hirt/Maisack/Moritz/Felde Tierschutzgesetz Kommentar 4th ed. 2023 § 1 para. 19 mwN; Lorz/Metzger, TierSchG Komm. 7th ed. 2019 § 1 para. 33 mwN). Suffering can also be physically and mentally debilitating; fear in particular is categorised as suffering in the commentary and case law (Hirt/Maisack/Moritz/Felde Section 1 TierSchG para. 24 mwN; Lorz/Metzger Section 1 TierSchG para. 37).

Damage occurs when the physical or mental condition of an animal is temporarily or permanently altered for the worse (Hirt/Maisack/Moriz/Felde TierSchG Komm. 4th ed. 2023 § 1 para. 27 mwN; Lorz/Metzger TierSchG Komm. 7th ed. 2019 § 1 para. 52 mwN), whereby completely minor impairments based on a physical or psychological basis are not taken into account. „The target condition of the animal is assessed on animals of the same species. The absence of body parts is regularly assessed as damage in the commentary literature“ (VG Hamburg decision of 4 April 2018, 11 E 1067/18 para. 47, also Lorz/Metzger TierSchG Komm. § 1 para. 52).

The breeding of Scottish Fold cats constitutes torturous breeding due to the single or multiple damages, pain and suffering described in detail under point 5: 

• Osteochondrodysplasia (see below for further details)
• Brachycephaly 
• Brachycephalic obstructive airway syndrome (BOAS)
• Polycystic Kidney Disease (PKD)
• Eye diseases (exophthalmos, entropion, corneal ulcers) 

A breeding ban for cats with Fd gene-determined „tipped ears“ is already recommended in chapter 2.1.2.1.3. of the so-called Qualzuchtgutachten.

The tipped ears typical of the Scottish Fold breed are caused by a genetic defect that leads to osteodystrophic skeletal changes in a quarter of the offspring. These changes, which can begin as early as a few months of age, are progressive, incurable and the associated pain and suffering are virtually untreatable. Skeletal deformities are undoubtedly associated with permanent pain, suffering and damage and not only impair the animals‘ movement and thus their quality of life, but also affect their life expectancy, depending on the severity. Due to the breeding-related cartilage defect, the articular cartilage is also impaired and typical behaviors such as jumping, hunting, running, etc. are impeded and thus the performance of species-specific behaviors is not possible or only possible to a limited extent under pain. This leads to not inconsiderable impairments of well-being and thus to suffering within the meaning of Section 11b TierSchG for the animals in question (Hirt in: Hirt/Maisack/Moritz/Felde TierSchG Section 1, para. 20,22).

The VG Ansbach, decision of 04.03.2019, AN 10 K 18.00952, consistently stated that Scottish Fold cats almost always suffer from osteochondrodysplasia, a bone and cartilage hereditary disease that leads to painful deformities and malformations and, among other things, restricts movement and social behavior.

The ears of the cat are a body organ that is of considerable importance for the species-appropriate behavior of the animal and has to fulfill certain functions. These breeding-related changes are associated with a considerable restriction of the species‘ own expressive and communicative behavior, as ears serve as signaling devices in social contacts (see Hirt in Hirt/Maisack/Moritz/Felde, Tierschutzgesetz, § 11b, para. 18). The VG Ansbach, decision of 04.03.2019, AN 10 K 18.00952, also states this: Scottish Fold cats suffer from so-called folded ears. Cats use their ears to express excitement, attention, defense and aggression, among other things. With folded ears, this form of expression is no longer possible, resulting in permanent damage.

For the legal justification of the classification of brachycephaly as torture breeding, see https://qualzucht-datenbank.eu/merkblatt-katze-brachycephalie.

It should also be noted that the description and assessment in this fact sheet refers to visible symptoms of torture breeding. In a large proportion of these animals there are additional hidden defects and dispositions which can be detected by additional examinations and/or genetic tests. For example, in addition to the visible changes in the ears of Scottish Fold cats, malformations of other ear structures have also been described.

Scottish Fold is therefore to be classified as defective/torture breeding within the meaning of § 11b TierSchG. Breeding knowledge not only suggests that the offspring must be expected to suffer pain, suffering and damage – it must also be regarded as proven that a more or less large proportion of the offspring will have to live with not inconsiderable restrictions to their well-being.

The breeding ban also extends to matings that produce or may produce heterozygous carriers if the hereditary trait is or may be linked to the occurrence of pain, suffering or damage in the heterozygous offspring. If a non-trait carrier is mated with a heterozygous trait carrier in the Scottish Fold cat, 50% of the offspring receive the mutated gene and thus become ill (see VG Ansbach, decision of 04.03.2019, AN 10 K 18.00952)

The prohibition applies regardless of the subjective facts, i.e. regardless of whether the breeder himself recognized or should have recognized the possibility of harmful consequences (Lorz/Metzger § 11b para. 4). Due to this objective standard of care, the breeder cannot invoke a lack of subjective knowledge or experience if the respective knowledge and experience can be expected from a careful breeder of the respective animal species.

Please also note the reasons for the court decision of the VG Ansbach, decision of 04.03.2019, AN 10 K 18.00952 and the judgment of the VG Ansbach of 16.11.2020 – AN 10 K 19.00988.

b) Austria

Cats with the defects/syndromes described above are classified in Austria as torture breeding according to § 5 TSchG.

In particular*, anyone who „breeds animals in a way that is foreseeable to cause pain, suffering, harm or fear to the animal or its offspring (torturous breeding), so that as a result of genetic abnormalities, in particular one or more of the following clinical symptoms occur in the offspring not only temporarily with significant effects on their health or significantly impair physiological life courses or cause an increased risk of injury“ is in breach of Section 5 of the Austrian Animal Welfare Act.
*The word „in particular“ means that the list is not exhaustive, but exemplary.

Breeding with cats that suffer from defects and the associated problems or are genetically predisposed to them is to be qualified as torture breeding.

The legal framework in Austria is clear and excludes animals that exhibit characteristics of torture breeding from breeding as well as from purchase or exhibition. Individual breeds are not listed in the law.
In the „Scottish Fold“ breed, the tipped ears make it easy for the breeder to recognize the torture breeding traits. The associated cartilage damage, which leads to pain, damage and suffering, is predictable.

c) Switzerland

Anyone wishing to breed with an animal that exhibits a trait or symptom that may lead to moderate or severe stress in connection with the breeding objective must first have a stress assessment carried out. Only hereditary stresses are taken into account in the stress assessment (see Art. 5 of the FSVO Ordinance on Animal Welfare in Breeding (TSchZV)). Cats with defects that can be assigned to burden category 3 are subject to a breeding ban in accordance with Art. 9 TSchZV. It is also prohibited to breed with animals if the breeding objective results in the offspring having a category 3 defect. Animals in category 2 may be used for breeding if the breeding objective is for the offspring to be less affected than the parents (Art. 6 TSchZV). Annex 2 of the TSchZV lists characteristics and symptoms that can lead to moderate or severe burden in connection with the breeding objective.
Skeletal deformities or malformations, degenerative joint changes/spondylosis, skull deformities with disabling effects on the position of the teeth, breathing ability and the position of the eyes, malfunction of the hearing apparatus such as deafness, progressive retinal atrophy (PRA) and persistent entropion are explicitly mentioned.

In addition, individual breeding forms are expressly prohibited in accordance with Art. 10 TSchVZ. In other cases, however, a breeding ban is only imposed on a case-by-case basis. Animals that have been bred on the basis of impermissible breeding objectives may not be exhibited (Art. 30a para. 4 let. b TSchV).

d) Netherlands

It is prohibited in the Netherlands under Article 3.4 „Breeding with domestic animals“ of the Animal Keeper Decree to breed cats that have a particular condition or external characteristic that may affect the health or welfare of the animal or its offspring. Breeding with a (Scottish) Fold cat violates Article 3.4 of the Animal Keeper Decree. This also applies to crossbreeding in which this genetic modification can be passed on to the offspring.

e) Norway

The National Veterinary Authority in Norway is tasked with providing guidance on existing legislation.
In 2021, the Norwegian Society for Protection of Animals (NSPA) asked the government agency for an official opinion on the legality of breeding Scottish Folds. In its response in 2023, the government agency stated that „breeding cats with folded ears is against the Animal Welfare Act“.
The breeding of Scottish Folds is prohibited under Section 25 of the Norwegian Animal Welfare Act.

Detailed legal assessments and/or expert opinions, if already available, can be made available to veterinary offices for official use on request.

10. Relevant jurisdiction

1. Germany

Ansbach Administrative Court, decision from 04.03.2019 – AN 10 K 18.00952

Ansbach Administrative Court, judgment of 16.11.2020 – AN 10 K 19.00988

2. Austria: 

Innsbruck District Court’s decision of 21.06.2022: IL/309210011951

3. Switzerland:

Criminal proceedings in Zurich (D-2/2013/3829) were discontinued, nothing is known about further proceedings.

4. The Netherlands: 

Breeding ban since 2014, implemented in 2019. From 01.01.2026 also a ban on keeping them

5. Belgium:

Breeding ban since 01.10.2021, in the city of Brussels already since 2019.

6. Norway:

Criminal charges were filed against two Scottish Fold breeders, but both were dropped. This means that there have been no criminal proceedings against breeders of Scottish Fold cats in Norway to date.

11. Order example available?

Yes.

Examples of orders are only made available to veterinary offices for official use on request.

12. Grants and subsidies

13.  Bibliography/ References/ Links

Only a selection of sources on the defects described above and, where applicable, general literature on breed-related defects in cats is given here. More comprehensive literature lists on the scientific background will be sent exclusively to veterinary offices on request.

Note: The description of health problems associated with the trait, for which there is not yet sufficient scientific evidence, is based on the experience of experts from veterinary practice and/or university institutions as well as publicly accessible databases or publications from animal insurance companies and therefore originates from different evidence classes.

As breeding and showing are international nowadays, the information does not usually only refer to the prevalence of defects or traits in individual associations, clubs or countries.

Sources:

AGRIA Pet Insurance Sweden. (2022). Scottish Fold Breed Report Veterinary Care 2017-2022.

Baumgärtner, Ph.D., W., & Gruber, Ph.D., A. D. (Hrsg.). (2020). Allgemeine Pathologie für die Tiermedizin (3. Aufl.). Georg Thieme Verlag. https://doi.org/10.1055/b-006-166359

Berteselli, G. V., Palestrini, C., Scarpazza, F., Barbieri, S., Prato-Previde, E., & Cannas, S. (2023). Flat-Faced or Non-Flat-Faced Cats? That Is the Question. Animals, 13(2), 206. https://doi.org/10.3390/ani13020206

BMEL Sachverständigengruppe Tierschutz und Heimtierzucht. (1999). Gutachten zur Auslegung von § 11b des Tierschutzgesetzes (Verbot von Qualzüchtungen). https://www.bmel.de/SharedDocs/Downloads/DE/_Tiere/Tierschutz/Gutachten-Leitlinien/Qualzucht.pdf?__blob=publicationFile&v=2

Bundesamt für Lebensmittelsicherheit und Veterinärwesen (BLV). (2015). Verordnung des BLV über den Tierschutz beim Züchten. https://www.fedlex.admin.ch/eli/cc/2014/747/de

Demir, A. (2024). Assessment of eye disorders in brachycephalic cat breeds—A retrospective study of 328 cases (2018-2022). Veterinarski arhiv, 94(3), 237–254. https://hrcak.srce.hr/file/460079

Dupré, G., & Heidenreich, D. (2016). Brachycephalic Syndrome. Veterinary Clinics of North America: Small Animal Practice, 46(4), 691–707. https://doi.org/10.1016/j.cvsm.2016.02.002

Ergi̇n, İ., Sai̇nkaplan, S., Uygur, A., & Şenel, O. O. (2025). The Effects of Animal-Related and Environmental Factors on Feline Entropion: A Comprehensive Cohort Study of 272 Eyes. Kafkas Universitesi Veteriner Fakultesi Dergisi. https://doi.org/10.9775/kvfd.2024.33011

Farnworth, M. J., Packer, R. M. A., Sordo, L., Chen, R., Caney, S. M. A., & Gunn-Moore, D. A. (2018). In the Eye of the Beholder: Owner Preferences for Variations in Cats’ Appearances with Specific Focus on Skull Morphology. Animals, 8(2), 30. https://doi.org/10.3390/ani8020030

 Fédération Internationale Féline. (2025). Breeding and Registration Rules: Cats not allowed for breeding-3.6.2 Cats suffering from (pseudo-) achondroplasia or osteochondrodysplasia. https://fifeweb.org/health-welfare-rules/#achondroplasia

Gralla, S. (2014). Vergleich der kornealen Sensibilität von brachyzephalen und mesozephalen Katzen unter besonderer Berücksichtigung des Brachyzephaliegrades (1. Aufl). VVB Laufersweiler.

Hale, F. A. (2021). Dental and Oral Health for the Brachycephalic Companion Animal . In Health and Welfare of Brachycephalic (Flat-faced) Companion Animals (1., S. 235–250). Taylor and Francis Group. https://www.taylorfrancis.com/chapters/edit/10.1201/9780429263231-14/dental-oral-health-brachycephalic-companion-animal-fraser-hale

Hubler, M., Volkert, M., Kaser‐Hotz, B., & Arnold, S. (2004). Palliative irradiation of Scottish Fold Osteochondrodysplasia. Veterinary Radiology & Ultrasound, 45(6), 582–585. https://doi.org/10.1111/j.1740-8261.2004.04101.x

Lutz, H., Kohn, B., & Forterre, F. (Hrsg.). (2019). Krankheiten der Katze (6., aktualisierte Auflage). Georg Thieme Verlag. https://doi.org/10.1055/b-006-163273

Meola, S. D. (2013). Brachycephalic Airway Syndrome. Topics in Companion Animal Medicine, 28(3), 91–96. https://doi.org/10.1053/j.tcam.2013.06.004

Niederländische Behörde für Lebensmittelsicherheit und Verbraucherproduktsicherheit. (o.J.). Zucht mit Katzen:Welche Katzenrassen unterliegen einem Zuchtverbot? Scottish Fold und andere Faltohrkatzen. https://www.nvwa.nl/onderwerpen/honden-en-katten/fokken-met-uw-hond-of-kat/fokken-met-katten

Niederländischer Staatssekretär für Wirtschaft, Landwirtschaft und Innovation vom 19. Oktober 2012, Nr. 291872, Direktion für Gesetzgebung und Rechtsfragen. (2024). Niederländisches Tierhalter-Dekret. Tierhalter Dekret. https://wetten.overheid.nl/BWBR0035217/2024-07-01/#Hoofdstuk3_Paragraaf1_Artikel3.4

Oksa‐Minaļto, J., Maggs, D. J., Akimova, J., Ilgaža, A., & Sebbag, L. (2023). Ocular surface physiology and aqueous tear secretion in cats of diverse cephalic conformations. Veterinary Ophthalmology, 26(S1), 109–118. https://doi.org/10.1111/vop.13051

 Park, J., Kang, S., Lee, E., & Seo, K. (2023). Prevalence of feline ophthalmic disorders in South Korea: A retrospective study (2009–2021). Journal of Feline Medicine and Surgery, 25(2), 1098612X231151478. https://doi.org/10.1177/1098612X231151478

Schlueter, C., Budras, K. D., Ludewig, E., Mayrhofer, E., Koenig, H. E., Walter, A., & Oechtering, G. U. (2009). Brachycephalic Feline Noses: CT and Anatomical Study of the Relationship between Head Conformation and the Nasolacrimal Drainage System. Journal of Feline Medicine and Surgery, 11(11), 891–900. https://doi.org/10.1016/j.jfms.2009.09.010

Schöll, K. (2021). Qualzuchtmerkmale bei der Katze und deren Bewertung unter tierschutzrechtlichen Aspekten [Justus-Liebig Universität Gießen]. https://doi.org/10.22029/JLUPUB-11345

Schweizerischer Bundesrat. (2024). Tierschutzverordnung (TSchV) Schweiz. FedLex. https://www.fedlex.admin.ch/eli/cc/2008/416/de

Srisowanna, N., Darawiroj, D., Choisunirachon, N., Thanaboonnipat, C., & Tabtieang, S. P. (2024). Morphological and Morphometric Variations of the Tympanic Bulla Between Domestic Shorthair and Brachycephalic Cats Utilizing Computed Tomography. The Thai Journal of Veterinary Medicine, 54(2), 175–182. https://doi.org/10.56808/2985-1130.3598

Universities Federation for Animal Welfare (UFAW). (o. J.). Scottish Fold Osteochondrodysplasia. Genetic Welfare Problems of Companion Animals. https://www.ufaw.org.uk/cats/scottish-fold-osteochondrodysplasia

Velie, B. D., Milden, T., Miller, H., & Haase, B. (2023). An estimation of osteochondrodysplasia prevalence in Australian Scottish Fold cats: A retrospective study using VetCompass Data. BMC Veterinary Research, 19(1), 252. https://doi.org/10.1186/s12917-023-03811-0