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How Fainting Goats Work


Fainting goats, when startled, tense up and fall over. It could take several seconds for them to regain movement. See more pictures of mammals.
John Foxx/Getty Images

The lives of goats, by all appearances, consist mostly of eating, climbing, butting heads and a whole lot of standing on top of things. One particular breed of goat, however, is known for a rather different trait: stiffening up and appearing to faint.

Footage of these fainting goats continues to make the rounds on video-sharing Web sites and cable animal programs. After all, what's more hilarious than watching an entire pack of goats keel over in unison every time a farmer runs up to them with an umbrella?

Yet despite all appearances, these goats (also known as myotonic goats, "Tennessee stiff-legs," "Tennessee wooden-legs," "nervous goats" and "fall-down goats") aren't simply weak of heart or abnormally prone to fright. In fact, fainting goats don't actually faint or lose consciousness at all during these episodes. Due to an congenital (present from birth) medical condition known as myotonia congenita or Thomsen's disease, the goat's muscles tense up when the animal is startled and don't immediately relax. Think of it as a full-body charley horse, except without the pain.

­The severity of the condition varies. Some fainting goats will stiffen up every time they're startled, others less frequently. Symptoms often lessen over time and some animals are able to better adapt to the condition. Younger goats are more prone to fall over and tumble when startled, but as they grow older, many eventually manage to avoid falling down altogether during an episode. They simply run away from a threat on stiffened legs. Older goats also tend to become more secure with their environment and startle less easily.

In this article, we'll take a closer look at this rare breed of goat. We'll look at how myotonic congenita works and how it affects the goats' lives. We'll also examine how they came to be considered a breed and why anyone would choose to encourage their fainting spells.

 

 

 

Why Fainting Goats Faint

To understand what happens when a myotonic goat is frightened and faints, it's helpful to first take a look at what happens under normal conditions. If a person were to chase after a goat unaffected by myotonia congenita, the animal's eyes and ears would relay the perceived threat to the brain, which would then send an electrical signal to the skeletal muscles (such as those in the leg and neck involving voluntary movement), causing a momentary tensing. This is often referred to as the fight or flight response.

Just think how it feels to be startled, or have a friend remind you. You'll find your voluntary muscles contract and tighten for a second. This is your brain telling your muscles that the time has come to possibly confront or run away from an immediate threat.

Normally, this tensing is followed by an immediate relaxing of the affected muscles, allowing a typical goat to actually turn and run away from a perceived threat. With myotonia congenita, however, the muscles tense and stay tensed before slowly relaxing. Think about that moment of muscle tension following a sudden fright -- now imagine it lasting 10 to 20 seconds.

Due to abnormalities at the cellular level, the voluntary muscles of myotonic animals receive the electric signal from the brain to tense and keep tensing instead of releasing -- sort of like a skipping record.

This happens because myotonia congenita affects a particular gene called CLCN1 (Choloride Channel 1). This gene is involved in the production and regulation of proteins, which are vital to the flexing and relaxing of skeletal muscles. Positively charged sodium ions relay the brain's message for the muscle cells to contract. Negatively charged chloride ions, which CLCN1 affects, tell the muscle cells to relax. Mytonia congenita results in an abnormal channel of chloride ions, which throws this relationship out of balance. The muscle cells wind up with more than enough sodium but not enough chloride, which causes abnormal repetitive electrical signals from the brain (such as those associated with being startled) to result in stiffness.

While the fainting goats often receive the most press, myotonia congenita can be found in various other animals as well, all the way up from mice to human beings.

The condition is hereditary, and can be either a dominant trait (the gene only has to be inherited from one parent) or recessive trait (the gene is carried by both parents). Where fainting goats differ from other myotonic animals, however, is that they're actually bred to encourage myotonia congenita in their offspring.

Some humans with the disorder take medication or undergo physical therapy in order to manage their condition, and a number of miniature schnauzer breeders use genetic screening to avoid producing myotonic puppies, but the fainting goat is bred, raised and encouraged to seize up and tumble.

In the next section, we'll look at why a goat breeder would consider myotonia congenita a desired trait.

Reasons to Breed Fainting Goats

Goats have a tendency to jump and climb, making them hard to fence in. When fainting goats begin to jump or climb, they'll faint instead,
Goats have a tendency to jump and climb, making them hard to fence in. When fainting goats begin to jump or climb, they'll faint instead,
Photo courtesy ropuszyca, stock.xchng

While myotonia congenita occurs naturally due to the genetic makeup of an animal, fainting goats only exist as a breed only because humans want them around.

It's hard to imagine an animal with myotonia congenita lasting long in the wild. If a predator was to approach, the animal would stiffen up, fall over and natural selection would take its course. The strong survive, the weak perish -- that is, unless human breeders are there to protect the weaker animals and encourage their traits. This is known as unnatural selection, and it can be seen in any number of domestic and farm animal breeding programs.

While myotonia congenita itself likely predates recorded history, the encouragement of the trait in goats and the resulting emergence of fainting goats as a distinct breed can be dated back to the early 1880s in Marshall County, Tennessee. Some accounts link the breed to a particular farmer named John Tinsley, who reportedly brought a number of goats exhibiting symptoms of myotonia congenita down from Nova Scotia, Canada. According to this account, the animals were bred by a local doctor, and a little more than 120 years later, herds of fainting goats can be found throughout the United States.

But why has this breed been successful?

Historically, humans have always selectively bred animals for two reasons: to encourage certain behavioral traits and/or to encourage certain physical features.

For example, a guard dog may be bred for aggressiveness. Toy and show dogs may be bred for appearance. Whether the purpose is to breed an animal for amusement or to carry out a particular task, there's a purpose driving the course of unnatural selection.

Fainting goats are no different and have been bred for three distinct purposes:

  1. For meat: As are the primary use for most farm goats, the fainting variety is often raised for slaughter. Goats are natural climbers and jumpers, so they're also natural escape artists when fenced or penned in. Extra effort is often needed on the part of farmers to keep the animals enclosed. Myotonia congenita, however, tends to curb the animals' natural inclinations, as the acts of climbing and jumping can also trigger fainting. Additionally, the excessive muscle tensing tends to result in greater muscle mass, less body fat and a higher meat-to-bone ratio than other breeds of goat.
  2. For amusement: Like many animals, fainting goats are also sometimes raised as pets. Some owners raise them for the uniqueness of their fainting spells, while others choose them simply because they're easier to keep in an enclosure. Like other breeds of goats, their temperaments and physical appearance often make them good companion animals.
  3. To accompany herds: Since a fainting goat would fall over or be reduced to a hobble following a fright, many farmers saw them as an excellent form of protection for sheep herds. If a predator such as a wolf or coyote were to attack the herd, the non-myotonic animals could run away, leaving behind any fainting goats either immobilized or hobbled by the fright. The herd would escape and the predators would focus on the easiest kill. But this use has largely fallen out of practice, and the degree to which it was actually used is uncertain.

Whether food or friend, fainting goats don't seem to be going away anytime soon. Numbering an estimated 3,000 to 5,000, the animals are recognized as an official breed and are raised throughout the United States. Enthusiasts have even established breed standards and regularly show their prize animals at livestock festivals.

Fainting goats are used for many purposes: as food, as amusement and as protection for herds.
Fainting goats are used for many purposes: as food, as amusement and as protection for herds.
David Silverman/Staff/Getty Images

To learn even more about fainting goats and myotonia congenita, check out the links on the next page.

Related Articles

More Great Links

Sources

  • "Breeds of Livestock" Oklahoma State University Department of Animal Science 08/02/96. http://www.ansi.okstate.edu/breeds/goats/myotonic/index.htm
  • "Genetics Home Reference" U.S. National Library of Medicine. 04/07. http://ghr.nlm.nih.gov/condition=myotoniacongenita
  • International Fainting Goat Workshop. http://www.faintinggoat.com/
  • Jody Workman, International Fainting Goat Association. Personal interview.
  • Jordan Crump, The Humane Society of the United States. Personal interview.
  • Kathy Guillermo, Director of Research, People for the Ethical Treatment of Animals. Personal interview.
  • Luginbuhl, Jean-Marie, "Breeds of Goat for Meat Goat Production and Production Traits" North Carolina State University College of Agriculture and Life Sciences. 01/98. http://www.cals.ncsu.edu/an_sci/extension/animal/meatgoat/MGBreed.htm
  • "MedlinePlus." U.S. National Library of Medicine. 05/16/2006. http://www.nlm.nih.gov/medlineplus/ency/article/001424.htm
  • Myotonia Congentia "How Stuff Works.com." 05/16/06 . http://healthguide.howstuffworks.com/myotonia-congenita-dictionary.htm
  • "Myotonia Congenita - Symptoms and Treatment" American Miniature Schnauzer Club, Inc. 03/02/00. http://amsc.us/myo-symp.html
  • "NINDS Myotonia Congenita Information Page" National Institute of Neurological Disorders and Stroke. 02/14/07. http://www.ninds.nih.gov/disorders/myotoniacongenita
  • Spangler, Nicholas. "Scared stiff: So-called fainting goats actually make decent pets" Miami Herald. 08/31/03. http://www.miami.com/mld/miamiherald/news/6658675.htm
  • "Tennessee Fainting Goats." Ark of Taste, Slow Food USA.. http://www.slowfoodusa.org/ark/myotonic_goat.html
  • Weaver, Sue. "Livestock & Pets - Myotonic Goats" Hobbyfarms.com. 07/07. http://www.hobbyfarms.com/livestock-and-pets/myotonic-goats.aspx