Hey guys! I've seen a major uptick of cats with folded ears circulating TSS! While that is fine, unfortunately there is also a fair bit of misconceptions and lack of information floating around as well, and has been treated more so as a design quirk than as the disabling condition it is. So, to help combat that, I have taken the time to put together a guide of everything you need to know about it! Osteochondrodysplasia / Folded ears in cats: What is it and why it is a debilitating condition for felines. What is Osteochondrodysplasia? Osteochondrodysplasia, or also known as Scottish Fold disease (SFOCD), is a genetic mutation found in the Scottish Fold cat breed. It is a developmental abnormality that affects cartilage throughout the body, causing the folded forward ears, along with a whole variety of disabling defects and abnormalities that start as early as 7 weeks to 6 months old, and progressively gets worse, and severely hinders quality of life. In cat rp terms: that means that any cat with folded ears (excluding as a TSS species trait like Icecats,) has Osteochondrodysplasia. There is no work around for this. If your cat has folded ears, they will be in a state of constant pain for their entire lives. Incredibly harsh sounding, I know, but unfortunately, it is true. Why it causes folded ears: Osteochondrodysplasia is a condition that causes a defect in cartilage. Folded ears in cats with the condition develop at around 3-4 weeks of age, and is due to the cartilage of the ear being unable to support the weight of the ear, causing the flopped forward look. Why that affects the rest of the body: Cartilage is an important structural tissue, and it plays a key role in the parts of the body that have no bones, or places that act as a buffer for bones such as the joints. It also is critical in the bone growth and development of young animals. To summarize how bone growth works: the skeleton of unborn animals are developed first as cartilage and is replaced by bone in a process called ossification. Endochondral Ossification, in particular, is the development method for most bones, specifically the long and short bones such as arms/legs, which is what I will be focusing on as that is the process that heavily utilizes cartilage. When developing bones, a hyaline cartilage template is formed, which has the same basic shape and outline as the future bone, and expands through interstitial growth and appositional growth. With interstitial growth happening from within to increase length and appositional growth from the external surface of existing cartilage to increase in width and thickness. From there, ossification commences within the primary ossification center located in the center of the diaphysis (bone shaft), and the perichondrium surrounding the cartilage model transforms into the periosteum, and the cells in the periosteum shift gears, maturing into bone-building osteoblasts rather than cartilage cells (chondrocytes). After the formation of the periosteum, the primary center grows hypertrophy which secretes needed proteins and enzymes, one of which being Alkaline phosphatase, which is what causes the calcification of the cartilage matrix. During the postnatal life, a secondary ossification center appears in each end of long bones, and cartilage is converted to bone in a similar process as described above, and cartilage residue persists in two locations: Articular cartilage, the joints, and the epiphyseal growth plate, which is responsible for longitudinal bone growth, which persists till skeletal maturity. So, as for why any of that is important, cartilage is important! And Osteochondrodysplasia, unfortunately, leads to defective endochondral ossification, defects in that critical cartilage and bone growth, leading to the effects and symptoms which I will lay out here shortly. Genetics: The Fd gene which causes this condition is autosomal dominant. That means that only one copy of the gene is needed to cause it. Cats that are heterozygous (only carrying one copy of the gene) tend to develop the deformities at a much slower rate than cats that are homozygous (carry two copies of the gene) which develop devastating effects early in life. All cats that are homozygous in the gene will be severely affected. Cats that are heterozygous will be affected at varying degrees, some less severe, some just as. But all around, regardless of if the cat is heterozygous or homozygous in the gene, the cat will be disabled because of the condition. Here’s about what to expect in symptoms, in both cases:
General symptoms: In all cats with Osteochondrodysplasia, the following physical symptoms are standard and to be expected, whether heterozygous or homozygous in the gene: -Lameness, often worse in hind limbs, causing difficulty in running or jumping and leading to a ‘bunny hop’ gait. -Skeletal deformities: misshaped bones and joints; shortened and thicker tail; thickened feet, often with the toes spread wide -Abnormal posture or walk, decreased joint flexibility and fused bones/joints (ankylosis) -Ear issues such as being more susceptible to ear mites and infections -Decreased energy -Poor grooming habits Arthritis and osteoarthritis is also to be expected, with some developing earlier than others. The Scottish Fold breed also has a heightened risk of fatal health conditions such as: -Hypertrophic Cardiomyopathy (HCM) -Polycystic Kidney Disease (PKD) What to expect in roleplaying a cat with Osteochondrodysplasia (Homozygous): -By 7 weeks (so under 2 moons) bone deformities and anomalies are already present. Simple things like running, jumping and playing will become progressively harder for the kit, and will only get worse over time, especially as arthritis develops rapidly. -By 6 months/moons, bone/joint fusions, bone growth and deformities, particularly around the hock and metatarsals, will already be severe and debilitating. -As time goes on there is osteoarthritis, limb deformity, reduced ability to bear weight, and affected cats may wind up unable to walk. What to expect in roleplaying a cat with Osteochondrodysplasia (Heterozygous): -Cats that are heterozygous in the gene can be just as severe as homozygous carriers, but it varies and most of the time is less extreme. -Even in the less extreme cases, the issues of affected individuals present as young as 6 months/moons of age. -Symptoms take longer to progress, but arthritis and osteoarthritis, bone/joint fusions, lameness, etc happen over time, and prevalent as the cat gets older and by as young as a few years old may be unable to walk. Most cats with the condition are able to get by and live relatively comfortable lives with the help of medical intervention, medications and surgeries, but even then unfortunately many cats cannot be helped even with said care and have to be euthanized due to the severity of the pain they live in. And with that, keep in mind that there is no human/twoleg medication or care in a warriors roleplay. (TSS Oriented) Icecat folded ears: Folded ears in icecats are not caused by Osteochondrodysplasia, and is in fact an evolved species trait, meaning that your goat cats are safe! (TSS Oriented) folded ears in Falconcats: On the flip side, Osteochondrodysplasia, unfortunately, would affect falconcat flight. While yes, birds do not have this condition, looking at the structure of bird wing bones and how they are classified as long bones, they would be affected by defective endochondral ossification, meaning that joint/bone fusion, arthritis and osteoarthritis, etc. would target the wings as well. So, realistically? Cats with folded ears shouldn’t be able to fly. Especially not in homozygous carriers. Heterozygous carriers may be able to fly short distances for awhile (as falconcats learn to fly at around 6 moons, which is when Osteochondrodysplasia really becomes noticeable in heterozygous carriers, and over time would probably be limited to gliding till they would be unable to carry their own weight. Cats with one folded ear (one floppy one straight): I hate to break it to my designer friends but this is literally genetically impossible, if the cat has Osteochondrodysplasia they have it, and it affects both ears. That’s it, that's all I wanted to say. In conclusion: I am not writing this to discourage anyone from roleplaying cats with folded ears, but more so providing this for purposes of awareness. A lot of people use the condition because they think that the folded ears are cute, and don’t consider (or just are not aware of) the significant health effects that it has on the cat. Or, in other cases, people who do make cats with Osteochondrodysplasia tend to not portray it properly, cherry picking the symptoms, toning down the severity of it, and all around not treating it as the incredibly painful and life-impacting condition it is. If you are going to make a kit in a litter with a disability or condition (whether Osteochondrodysplasia or anything else really) please take the time to genuinely consider and research the effects it will have on the kit’s life. Conditions shouldn’t ever be used as a design quirk or to give a ‘vibe/aesthetic’. Doing so is a disservice to that design and the condition it now represents. And yes, it is that important. Proper representation is important, whether in mainstream media or in silly battle cat roleplays. That is all, thank you for coming to my ted talk. Sources inside project
