What type of cats were originally used to make catgut suture material (stitches), and violin strings? originally appeared on Quora, the place to gain and share knowledge, empowering people to learn from others and better understand the world. You can follow Quora on Twitter, Facebook, and Google Plus.
What do cats, tennis, doctors, cows, and violins have in common? The answer is… catgut!
Catgut sutures have been around a long time. Yes, that’s what’s used to make absorbable stitches, even today. Absorbable stitches are those that don’t need to be removed. They just kind of break down and become part of your skin. Making catgut is a pretty lucrative business, as there is still a fair demand. Where do they get all this catgut? Umm… you know when a vet puts your cat to sleep and then takes them into the back room? Well……
The truth is… if your cat is sitting with you as you read this, and is making a face like the cat above, you can tell your pussy not to worry; it isn’t, and never was, made from actual cat guts. Theoretically, you could use your cat’s intestines to make catgut string, but when compared to the string you get from cows and sheep, it’s not worth the trouble. A cow intestine can produce catgut string that is up to 160 feet long. Your cat’s intestine is small potatoes compared to that. So, why the heck is it called catgut, when no cats were harmed in the production of this string? I’ll get to that in a bit. First, let’s find out exactly what this string is.
As I just said, it comes from the intestines of cows. Mostly cows, these days. Sometimes from sheep, pigs or even horses… but cow catgut is the biggest current industry. When cows are slaughtered for meat, the intestines are saved and processed. Here is a cross section of intestine. 
The part we want, to make catgut, comes mostly from the submucosa, and the externa layers. These two layers contain the collagen, which is what we’re looking for. Collagen is found throughout the bodies of mammals, and some other vertebrates. Wherever structural strength and elasticity is required in soft tissue, you may find collagen there. Skin, for instance; strong and elastic. The intestines also need to be strong and elastic, for when we eat a lot of food, in order for the intestines to stretch without bursting, and then to contract back to normal size after food passes. This collagen is made up of strong stretchy fibers.
At slaughter houses, the intestines are usually slit in half, thirds, or quarters, lengthwise. This would make different thicknesses, for different uses. So the above cross-section would make two, three, or four long lengths. These are then soaked in a series of solutions and caustic solvents, which dissolves away all the tissue except for the strong collagen fibers. Once all these fibers are clean and pure, it is then stretched, twisted, and allowed to dry under tension. What remains is catgut string; pound for pound, one of the strongest strings there is. In that regard, it’s stronger than a comparable weight of steel wire, in fact.
Various gauges (diameter) of catgut are produced, depending on what its ultimate use is to be. There are three main industries where catgut is used. The first is as surgical suture material. In western countries, it is being replaced by other materials that also are absorbed into the body. But the market is still strong in developing countries. So… you have the medical market.
Sports! Namely tennis and other racket sports, is also where you can find a use for catgut. For sporting purposes, it is made much thicker. Catgut was the original racket material.
It is biological material, so in time, it does degrade. But it offered the perfect combination of strength and “spring”. Another sport that has used catgut is archery. Catgut has long been used to string bows, at least as far back as ancient Egyptian times. And as we know, the Egyptians really loved their cats. So clearly they didn’t use their intestines for their bows. No, it was cattle, even then.
And finally, the third major use of catgut is for violins.
Catgut was the original violin string material. These days, there are many other types of strings, but you can still find catgut in many professional orchestras, on a variety of stringed instruments, from classical guitars, to those giant pedal harps that rest against your shoulder and make Heaven sounds.
So there you go, now you know that, whether you have a large cut that has been stitched up or you are playing tennis or practicing your archery or even if you are playing your violin, viola, or harp, no kitties were hurt.
You’re still wondering why it was ever called catgut, I’m sure. Well, the “gut” part is obvious, it’s made out of guts, which itself is a very old word. But the “cat” part actually started out as “kytte” (pronounced “kit”). What is a kytte? This is a kytte. 
That’s the front and back of a kytte… a medieval-era mini-violin. It was so mini, that it was stored in the pokett ( [pokytte] 15th century), which was derived from the Old French poque, or bag. Traveling minstrels could whip out their kytte, play a lively tune or three, and then put their hardy instrument back into their pokett, without worrying about the delicate frailty of a normal sized violin. These instruments were the perfect mingling of a horsehair bow, rubbing against a cow gut catgut, in perfect concert with each other. Catgut (kytte gut) is so named because it is gut that is used to string your kytte. Simple as that. It has nothing to do with felines, whatsoever.
There you go, the story of catgut.
While you’re here, and since we were speaking of harps and kyttes, you might find these two ladies fascinating. They are coincidentally named Camille and Kennerly Kitt!
They also play Metallica, Iron Maiden and a lot of other cool stuff! What a way to strum catgut! Even Black Sabbath! This Sabbath tune is so rad.
I was going to make some typical “man” comment about these two beauties being welcome to strum for me anytime… but I won’t stoop that low. I have a gut feeling you’d find that as just crass.
But to get back to catgut, the short version is, poque is Old French for a bag. And yes, that is where pig in a poke (poque) comes from; a pig in a bag. A small poque, or small bag, was a poquette in Old French. The Old English version was pokytte. These pokyttes got attached to clothes, and became today’s pocket.
Meanwhile, the small violins were made, that would fit in a pokytte. They were called pokytte violins, later shortened to kytte violins, and eventually, colloquially, just kyttes. The strings on them were called kyttegut, by the street performers; in time becoming catgut. Voila!
EDIT: There are some people who suggest catgut is derived from “cattle gut”. Although this sounds reasonable, there was an actual instrument called a “kytte”, and what they were strung with was referred to as “kyttegut”. You are free to choose either version.
 Image courtesy of University of Guelph
 Photo of pochette violin by
Photo Credit: dozet/Getty Images