What is surgical catgut and where does it come from?

Despite its name, catgut isn’t actually made from the guts of cats.

It was originally derived from the intestines of sheep, which were dried and twisted into thin, strong strands. While catgut could be made from the intestines of cows and other animals, there’s no evidence that cats were ever its source.

So why isn’t it called “sheepgut”? There are several theories, but the one we like best is that the misnomer came into use at a time when violins were strung with the intestinal strings. “Kit” was another name for a fiddle.

Regardless, catgut is on its way out as a surgical suture. Other biological sources for sutures include silk and hair. Since the outbreak of bovine spongiform encephalopathy (BSE, or mad cow disease), doctors and patients have worried about catgut carrying the disease.

Synthetic materials have proven superior to biological catgut over the last decades; the worry over contracting BSE from natural sources has further hastened this trend.