The term "catgut" does not come from cats. It derives from Middle English "kit," meaning fiddle, and "gut," referring to instrument strings. Strings were made from animal intestines, including sheep and goats. These materials were also used for surgical sutures, leading to the term "catgut."
Catgut sutures were used for internal stitching, ophthalmic surgery, hernia repair, and obstetrics. Synthetic alternatives like nylon, polyester, and polypropylene gradually replaced them due to concerns about disease transmission and allergic reactions. Today, "catgut" is considered a misnomer for modern surgical sutures.