Most everyone knows that glue is somehow made out of horses. And that old, sick, or tired horses may just end up at the glue factory. You see and hear references of it in cartoons, movies, books, and other media- and even in daily life- all the time. So it just has to be true, right? Right?
Wrong. This is a myth that just won't quit, albeit one that is rooted in fact. There was a time in history, about a century or more ago, when there was truth to this. Horses then were primarily working animals, and there was little use for one when it became too old or sick to pull its own weight, so to speak. In those years, many horses were in fact taken to glue factories that would slaughter and render them.
Glue was derived from boiling the hooves, bones, and hides of horses and other hoofstock. Gelatin comes from the hooves of animals, and was one of the key ingredients for making adhesives.
Many of the popular brands of glue that are made today, including Elmer's, are entirely synthetic. They are made of various chemicals, not horses or other animals. Elmer's even states this on their own website, in the Frequently Asked Questions.
Some glues are still made from animal parts, but mostly today that comes from cattle. Because of the high demand for beef, especially in the fast food industry, there is an abundance source of slaughtered cattle to get the necessary parts from, since all the food industry cares about is the meat.
There is a slight chance that glues made from animal origins may include horse parts, but unlike a hundred years ago, horses are no longer killed for the sole purpose of making glue. Horses that are already dead from other causes often end up in rendering plants, where they may have their fat made into soap, their hides made into leather, their bones and organs crushed and made into pet food, and yes, their hooves made into gelatin, which may be turned into glue. But nobody really 'takes their horse to the glue factory' anymore. If they did, they'd be turned away and probably laughed at!
So while it was at one time true that horses often ended up at the glue factory, this is an obsolete idea, and it is high time that this tired myth be put to rest once and for all.
Although there is one Internet humorist who suggests that Super Glue is made from unicorns. And that, I hate to admit, just might be true!