Scottish Fold cats are born with folded ears. The folded ears are a product of a genetic mutation, and most mutations are harmful to the species. Normal cats have erect ears, so almost all Scottish Fold cats have some degree of skeletal defect. 
Symptoms of the disease in Scottish Fold cats:
1. If a Scottish Fold cat exhibits an abnormal sitting or sleeping posture, it may indicate that the cat is ill.
2. A short, stiff tail that cannot bend or wag is also a clear symptom of the disease in Scottish Fold cats. At the same time, the joints of Scottish Fold cats will also become stiff, deformed, and unable to bend. Accompanying symptoms include swollen paws that cannot be extended or retracted, pain when pressed, and abnormally thickened paw pads.
3. After the onset of the disease, Scottish Fold cats will feel body pain. In order to relieve the pain, Scottish Fold cats will lift their paws to change their center of gravity and reduce the pressure of their body weight on their joints.
4. The cat suddenly becomes listless and loses its appetite.
5. When a cat sits upright, the pads of its hind paws do not touch the ground, and its nails grow abnormally.
