Catgut down to the desired diameter using a centerless grinder. After drying and polishing, workers bleach and disinfect the strings using sulfur dioxide, dye them if necessary, and sort them into sizes. Catgut sutures are normally treated with a chromium salt solution to resist body enzymes, to slow the absorption process, and are called catgut chromic sutures—whereas untreated catgut sutures are called catgut plain sutures. Catgut Catgut is a type of cord that is prepared from the natural fibre found in the walls of animal intestines. Catgut makers usually use sheep or goat intestines, but occasionally use the intestines of cattle,
Catgut infection. Catgut sutures remain in use in developing countries where they are locally less expensive and easier to obtain. Catgut treated with chromium salts, known as chromic catgut, is also used in surgery. Natural gut is still used as a high-performance string in tennis racquets, although it had more popularity in the past and is being displaced by synthetic strings. To prepare catgut, workers clean the small intestines, free them from any fat, and steep them in water. Then they scrape off the external membrane with a blunt knife, and steep the intestines again for some time in potassium hydroxide.