There has been some misunderstanding of which animal catgut used as strings on musical instruments is from. Many people have thought it was made from cat intestines. The intestine part is correct, but cats (thank goodness) aren’t the animals.

The animals were sheep, goats, cattle, hogs, horses, mules or donkeys. My girl would still frown about this. Who can blame her when she’s a vegan? I’m just glad they didn’t get the strings from cats.

https://en.wikipedia.org/wiki/Catgut