A dwarf cat is any domestic cat which has the condition of dwarfism due to a genetic mutation. Unlike undersized cats of normal proportions, dwarf cats display symptoms of osteochondrodysplasia—genetic disorders of bone and cartilage, typically manifested as noticeably short legs. Since the mid-twentieth century, cat breeds with embedded dwarfism have been developed for commercial sale. The ethics of their selective breeding is hotly debated, and many countries prohibit it as cruelty to animals.