Katgut

Katgut is a term used for natural strings made from the cleaned and processed intestines of animals, most commonly sheep or goats, though cattle intestines are sometimes used. The name is a historical misnomer, as it does not come from cats. The material is a collagen-based fiber that can be drawn into thin threads for various uses.

In medical contexts, katgut refers to absorbable sutures made from animal intestines. The intestines are cleaned, treated to remove fats and proteins, and then processed into fibers that are braided or twisted into suturing threads. Some sutures are coated with chromium salts (chromic catgut) to slow degradation. Absorption occurs over weeks to months, and plain gut tends to absorb faster than chromic gut. Modern surgical practice increasingly favors synthetic absorbable sutures made from polymers, but catgut is still used in some settings and regions.

In musical contexts, “gut strings” or katgut strings were commonly used for guitars, violins, lutes, and similar instruments before the rise of metal and synthetic strings. Gut strings produce a bright, responsive tone but are sensitive to humidity and temperature and have less predictable stability. Today, nylon or steel strings are predominantly used for modern instruments, while gut strings remain favored by some players of early-music or historically informed performances.

Safety and regulation apply to both uses, with sterilization and quality controls essential for medical sutures. In medicine, the shift toward synthetic alternatives reflects concerns about tissue reaction, variability, and consistent performance, though organ-derived gut products continue to have niche applications.