Ever wondered if glue is made from horses? Are horses really sent to the glue factory? Is any glue vegan? This guide will help you sort through the myths and facts of horse glue, and learn which glues are vegan.
Table Of Contents
- Is Glue Made from Horses?
- What Is Glue Made Out Of? Is Glue Vegan?
- A (Very Abridged) History of Glue
- Glues of Animal Origin (Not to Be Confused with Animal Glues)
- Types of Vegan Glue
- Which Major Glues Brands Are Vegan?
- Final Thoughts On This Sticky Subject
Is glue made from horses? – Parts of horses have been used to make glue, including their skin, hooves, and connective tissues. However, there is no evidence that horses were used more than any other animal. While there is a possibility that parts of horses slaughtered for their meat today are used for glue, the vast majority of animal glue is made from cows and pigs slaughtered for their meat. Overall, the concept of sending horses to the glue factory appears to be an overblown stereotype—and one the internet has only perpetuated. Read below for more on the myths vs. facts about horse glue.
Is glue vegan? – Most glue made today is vegan. The majority of glues are entirely synthetic and not of animal origin. You can also find some natural, plant-based glue if you’re wanting to avoid petrochemicals. However, some glues are made from animals. Read below for more on vegan glue options and how to know if a product contains animal glue.
At one point or another, you’ve probably heard the old saying about “sending horses to the glue factory” when they get old and sick. Jokes about making horses into glue pop up in places like the Simpsons,1 and—shockingly—copious internet memes.
So if you’ve ever wondered if glue really is made from horses, you’re not alone. And if you’ve ever tried Googling it, get ready to hear an entirely different answer. tweet this
From the myths and facts about horse glue, to vegan glue options, to how to tell if a product contains animal glue, I’ll guide you through this sticky subject.
Horse skin, bones, connective tissues, and hooves can be used to make glue. However, while countless blog posts around the internet claim that horses have been made into glue for thousands of years, I could not find any solid evidence that horses were ever used more than any other animal.
In fact, horses were not even directly mentioned in any of the academic, industry, and historical-minded sources I read.2
But the idea that glue was—or is—primarily made from horses is most likely a myth, overblown stereotype or—my personal guess—a manifestation of speciesism.
If you’re not familiar, “speciesism” is “a prejudice or attitude of bias in favour of the interests of […one…] species and against those […] of other species.”4 A simplified example is how we love dogs but eat pigs.
Speciesism presumes that humans determine the inherent value of other sentient beings.
In regards to this topic, our human bias for horses over those beings we deem “food animals” became extremely apparent when I compared keyword research (meaning what people Google) to academic research (meaning reality). This may sound boring, but stick with me for a moment.
As of this writing, the phrase “is glue made from horses” is searched for 5,000 times a month, while the phrase “is glue made from cows” receives 60 searches a month.
But, if you want to “get clicks,” you have to write about what—or whom—humans care about, which only continues to reinforce the valuing of some lives over others—further pushing into obscurity the sentient beings we most exploit. tweet this
The result is a self-perpetuating internet machine of blog posts composed of nearly-identical dumps of uncited claims.
One such uncited claim is that horses were—and are—explicitly killed for glue.
In 2006, the United States implemented a back-door ban on horse slaughtering by pulling federal funding for inspections, essentially shutting down the domestic horse meat industry.8
This only resulted in horse slaughter shifting to Canada and Mexico, subjecting horses to multiple days of transportation under brutal conditions in addition to a horrific death.
A 2011 report from the United States Government Accountability Office found that “nearly the same number of U.S. horses was transported to Canada and Mexico for slaughter in 2010—nearly 138,000—as was slaughtered before domestic slaughter ceased.”9
Additionally, the report found that horse welfare overall declined since the ban, “as evidenced by a reported increase in horse abandonments and an increase in investigations for horse abuse and neglect.”10 Off the back of this report, then President Barack Obama lifted the ban on horse slaughter in the United States.
As much as we humans love horses over cows, pigs and chickens, even their perceived value has its limits. Even champion race horses are treated as disposable commodities, killed as soon as they stop making money.
To learn more about our treatment of horses, please see my Horse Riding Ethics series.
Another thing people frequently ask in regards to this topic is “when did they stop using horses for glue?” Many of the top-ranked articles answered this inquiry with an identical excerpt copied verbatim from Wikipedia, claiming that ranchers in the 18th and 19th centuries sent horses to the glue factory, but that animal glue has “recently” been replaced by other adhesives.11 A claim which—it’s important to note—has absolutely no citation on Wikipedia, nor even a “citation needed” indicator.
Also without any citation is the claim that “Some companies, such as those in Canada, still produce animal, hide and hoof glues from horses.”12 As we’ve covered, horses today are slaughtered for their meat. And it’s entirely possible that some of their body parts are used to make glue.
But again, the vast majority of animal glue is derived from cows and pigs. For an idea of the disparity, in the same year that 138,000 horses from the United States were sent to slaughter,13 34.2 million cows and 110.3 million pigs were killed in the US alone.14
These days, most glues you’ll encounter are synthetic rather than animal-derived. So yes, most glues are vegan. But animal glues and glues of animal origin are still manufactured.15
While you would most likely know if you were purchasing hide, bone, or fish glue in their pure form, you’re more likely to encounter glues made from animals within finished products like shoes, cosmetics, and musical instruments. Later on in this article, we’ll address how to tell if a product is made with glues of animal origin.
The history and modern technology of adhesives is more vast and complex than I could possibly hope to cover. So, let’s explore a (very) abridged history of glue.
- Middle Paleolithic period (about 250,000 to 30,000 years ago):
Glue is nothing new. Perhaps the oldest evidence of glue is a plant-based birch bark adhesive dated back to the Middle Paleolithic period16 (about 250,000 to 30,000 years ago).17 In fact, birch bark glue may be the first known synthetic material our ancestors ever created.18
- Within the 7th millennium BCE (about 8,000 years ago):
Possibly the first known usage of animal glue (from animal collagen) dates back to over 8,000 years ago19 (within the 7th millennium BCE). Artifacts found in a cave by the Dead Sea were coated with a collagen-based adhesive, most likely derived from animal skins.20 This glue was “used as a protective, waterproof lining on rope baskets, containers, and embroidered fabrics, and was used to hold together utensils. It was also used to make a crisscross design on human skulls.”21
- Early Egyptians:
Early Egyptians used a range of glues of both plant and animal origin, including: albumin (blood), animal glue of some type (from collagen and/or keratin), beeswax, clay, gum, gypsum, natron, resin, salt, solder and starch.22
- The Greeks and Romans (between 1CE to 500CE):
The Greeks and Romans further refined and developed adhesives.23 Roman naturalist Pliny the Elder wrote rather extensively about adhesives, claiming that “[t]he finest glue is made from the ears and genitals of bulls.”24
- Nerdy side-note:
While researching whether glue is made from horses, I found plenty of blog posts stating that the Egyptians and other ancient cultures made and used “horse glue.” However, I was not able to find any primary historical sources to corroborate this claim. Animal glue—made from the skins and connective tissue of animals—was used, but horses were never specified.25
- Theophilus Presbyter (in a text circa 1110 – 1140):
Jumping ahead to the 1100’s (I did say this was an abridged history), the pseudonymous author Theophilus, wrote instructions for preparing a variety of glues, including those from fish bladders, cheese, animal skins, horns, and blood.26 Theophilus never specified using horses to make glue. He did, however, describe covering tablets with “the untanned skin of a horse or ass,” but for adhesive used what he referred to as “the glue of cheese” (what we now call casein glue).27
- First animal glue factory (around 1690):
Fast forward to about 1690 when the first commercial factory for producing animal glue from hides was set up in Holland.28
- Glue patents issued (first in 1754):
A flurry of glue patents were issued after the first (for fish glue) was granted in 1754 in the UK.29
- Glue factories in the US (first in 1808):
The first animal glue factory was started in the United States in 1808,30 and by 1900 there were multiple factories manufacturing glue from a variety of sources.31
Up until the 1920s, most adhesives were either animal or plant-based in origin, but the development of synthetic polymers rapidly overtook natural glues.32
As I stated earlier, the vast majority of adhesives today are entirely synthetic. However, as glues of animal origin do still exist, let’s cover some of them.
Glues of animal origin vary in their source and manufacturing process. The most well-known category are animal glues. The term “animal glue” is thrown around rather casually to refer to any glue derived from or containing ingredients of animal origin.
However, I found that the more academic, industry, and historical-minded sources33 specified that “[t]he term animal glue usually is confined to glues prepared from mammalian collagen”34—sourced primarily from skin, bone, and connective tissues.
Glues prepared from keratin—another structural protein, primarily sourced from hooves and horns—are usually also included.35 I will hold to this distinction, referring to the greater umbrella as “glues of animal origin.”
Before we get into specific types of animal-based glues, I wanted to address the question of whether animals are killed solely to make glue. Nothing in my research has shown this to be the case. tweet this
Animal glues primarily use parts of animals slaughtered for their meat, or after their bodies give out from the demands of the dairy industry.
However, animal glue cannot accurately be deemed “just a byproduct” of the meat industry.
The animal glue market was valued at $67.4 billion in 2018,36 with a projected compound annual growth rate of 5.5% through 2030, according to some global market analyses.37 While another analysis strongly cautioned about growth challenges for the animal glue market,38 there’s no doubt that it’s a fully developed industry all its own.
So, while animals aren’t killed explicitly for glue, animal glue—like leather—is a coproduct rather than byproduct of the meat and dairy industries. To learn more about what a coproduct is, check out my video and article “Is Leather a Byproduct of the Meat Industry?“
As I “nerdsplained” earlier, the term “animal glue” usually refers to glue derived from the skin, bones, connective tissues, hooves, horns and sometimes teeth of mammals.39 While there are many ways to subdivide animal glues, I’ve grouped them by their primary structural protein: collagen and keratin.
The most prominent animal glues are those made by extracting the collagen from animal skins, bones and connective tissues through boiling.
Collagen is a fibrous structural protein present in the extracellular matrix and connective tissue of animals.40 It’s sometimes referred to as the “glue” that holds the body together. The word collagen is derived from the (potentially Latinized)41 Greek root κόλλα (kolla)—meaning “glue” or “gum”—and “gen”—meaning “producing” or “giving birth to.”42
One leading manufacturer of animal glue claims they now primarily use recycled gelatin from the pharmaceutical industry for their hide glue, rather than boiling hides themselves.44 The recycled gelatin is still initially derived from animals.
Nerdy side-note: One of the more absurd claims I saw parroted across top-ranking blog posts in response to why horses are used to make glue was that they contain “a lot of collagen”—a trait attributed either to their size (fair, and equally applicable to cows) or some unexplained anomaly of their biology that’s just “stuffed them full of collagen” beyond any other animal on earth.
Hide glue—made specifically from animal skins—is said to be of higher quality than bone glue.45 Most hide and bone glue is produced from cows and pigs slaughtered for their meat or after their bodies give out.46
Rabbit skin glue is just what it sounds like—glue made from rabbit skin, though other small mammals are sometimes included.47 According to a review of the global animal glue market, rabbit skin glue was “observed as the leading segment in 2017 and is projected to maintain its dominance throughout 2030,” and is “widely used by manufacturers of pet food, pharmaceuticals, [and] cosmetics.”48
Less widely used animal glues are those made from extracting keratin—another structural protein—by boiling hooves and horns.49 Hoof glue is still used in some woodworking, though it seems more smaller-scale artisan woodworkers than commercial manufacturing.50
Other glues of animal origin that don’t fall under the technical term “animal glue” include fish, casein, shellac, and albumin glues.
- Fish Glue & Isinglass:
Fish glue, at one point, was one of the more prominent animal-derived glues.51 If you remember, the very first glue patent was for fish glue.52 Fish glue can be produced from the skin of “non-oily” fish, along with their bones.53
Another kind of fish glue is derived from isinglass, a form of collagen procured from the swim bladders of fish.54 Isinglass is more commonly used in the fining of some wine and beer. For more on that, see my article and video “Is Alcohol Vegan?”
While Isinglass and fish glue may seem like niche products, the impact of the global fishing industry is a threat to all life on this planet. To learn more, please see my article and video “Empty Oceans.”
- Casein Glue:
Casein is a protein found within milk, and is originally what Elmer’s glue was made with (more on that later). Casein glue is what Theophilus referred to in his 12th century writings as “the glue of cheese.”55
You may be more familiar with shellac as a finish for wood, or the shiny coating on candy and some fresh fruit. Secreted from the female lac beetle, shellac is a resin that can also be used for adhesive purposes, though its usage has declined due to its cost.56
- Blood Albumin & Egg Albumen Glues:
As we learned in the brief history of glue, blood albumin (a protein) and egg albumen (what we call “egg whites”) have been used to make glue,57 and may still be used in limited applications.58
As I mentioned earlier, animal glue is still used in some modern manufacturing. According to one of the leading global producers, animal glue may be used in a variety of products, including: “rigid and cardboard boxes, bookbinding, abrasives, match heads, laminating, paper crimping, antique restoration, woodworking, gummed tapes, glass chipping, musical instruments, stationary, paintballs, birdseed molds, art canvas sizing.”59
A report on the global animal glue market states that footwear holds a “significant share” of animal glue use, also mentioning pet food, pharmaceuticals, and cosmetics.60
The best way to know if a product contains animal glue—or any animal-derived ingredients, byproducts or coproducts—is to contact the company. I will say that this can be a frustrating—if not fruitless—endeavor depending on the company.
If in doubt, see if there is an alternative product that you can verify, but don’t lose yourself in tracking down every adhesive in every product. Oftentimes, the information isn’t even available.
When it comes to necessary prescriptions that may contain gelatin, please refer to my video and article “Is Medication Vegan?” Overall, focus on the big things. When buying actual glue, buy vegan. These days, you kind of have to make an effort not to! tweet this
As we learned in our abridged history, the first known glue was entirely plant-based. Long before the advent of synthetic glues, natural adhesives were made from a variety of non-animal sources. While most commercial glues are now petroleum-based, natural plant-based glues are still in use today.
There is a developing interest in (re)expanding the usage of bio-based polymers for their environmental advantages over synthetics: they’re biodegradable, non-toxic, and are said to have lower carbon footprints.61
- Starch & Dextrin Adhesives:
Starch is an inexpensive and abundant natural polymeric carbohydrate found in plants. Dextrin is simply starch that’s been further processed.62 For adhesives, starch is most commonly derived from maize, corn, potatoes, rice, and wheat.63
Starch glues are commonly referred to as “paste,” and are widely used in bonding paper products—like food and other product packaging, wallpaper, book-binding, and corrugated boxes—as well as in textiles.64 Due to their wide availability, low cost, non-toxicity, biodegradability, heat-resistance, and other advantageous attributes, starch and dextrin-based adhesives still hold their own in a largely synthetic market.
- Cellulose Adhesive:
Cellulose is “the most important skeletal component in plants,” and is—according to one fawning journal article—”an almost inexhaustible polymeric raw material with fascinating structure and properties.”65 In the glue-world, cellulose adhesive is use for such applications as wallpaper, window decals and apparently to secure the packaging of cigarettes.
- Natural Rubber:
Natural rubber is sourced from certain trees and plants,66 and used primarily in pressure-sensitive adhesives.67 While natural rubber is plant-derived, there is serious concern over deforestation, environmental impact, and sustainability.68
As I stated early on, the world of synthetic adhesive is far beyond the scope of this video and article. If you really want to dive in, feel free to read one or more of the multi-hundred-page textbooks in my bibliography!69
At a very high-level, most synthetic glues are petroleum-based.70 So while animal-free, there are issues of environmental sustainability.
Synthetic adhesives can be divided into the major type classifications of: thermosetting, thermoplastic, elastomeric, or combinations thereof.71 Synthetic glues include everything from pressure-sensitive adhesives made with synthetic rubber, to two-part epoxies, to hot glue, to contact cement, and countless others.72
Rather than get lost in a chemistry lesson, let’s touch on which major glue types and brands are vegan.
As we’ve discussed, most major glue brands and types of glue are vegan. I’ll only highlight a few, but recommend I’m Going Vegan’s vegan glue guide for more brand-specific information.73
Elmer’s glue is vegan, though it wouldn’t have been in its initial form. Originally produced by the Borden Company, a conglomerate with its roots in the dairy industry, Elmer’s was initially casein glue (made from milk).74
However, Elmer’s glue was never made with horses, hooves, hides, or other animal components.75 The bull mascot on the bottle is not a nod to its ingredients—Elmer the bull is the “husband” of Borden Dairy’s mascot, Elsie the cow.76 Modern Elmer’s glue is entirely synthetic.
All Gorilla Glue is vegan. Not only do Gorilla Glue products not contain animal-derived ingredients, but they are also not tested on animals. According to correspondence with the company relayed on I Am Going Vegans’s glue guide, Gorilla Glue stated:
- “We believe strongly in the inherent rights of animals. Therefore, The Gorilla Glue Company does not perform any kind of animal testing, and there are no animal by-products or animal-derived ingredients in any of our products.”77
As the author of the guide notes, it’s pretty rare for a company to affirm the inherent rights of animals in a response about their products’ ingredients.
Super Glue is vegan. As is Krazy Glue, and any superglue produced by Elmer’s, Gorilla Glue, and most likely other brands. The quick-setting adhesives we commonly call super glue is a category of cyanoacrylate adhesives.78 Chemically derived from acrylate monomers, superglues contain no animal ingredients.79
Eyelash glue honestly was not on my radar in the slightest. But apparently, most eyelash glue is vegan as they are made with the same fast-drying cyanoacrylate adhesives as superglues.80 Two examples of vegan eyelash glues are:
- Duo eyelash glue is vegan (Duo LashGrip)81 – the company (Ardell) also states they do not test on animals in their FAQ82
- House of lashes glue is vegan – the company also states they do not test on animals in their FAQ83
It’s time to “stick” the landing of this subject (couldn’t help myself). Major takeaways:
- The myth of horse glue is likely driven by the fact that we humans care more about horses than the cows and pigs most animal glue actually comes from.
- When it comes to buying glue, you’re likely clear of animals.
- When it comes to pre-made products, do your best and find alternatives if possible.
I hope this has been a helpful guide to glue—and perhaps has also shed some light on the speciesism underlying our focus on horses being made into glue.
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— Emily Moran Barwick