Is this claim about equine anatomy true?

Is this claim about equine anatomy true?

We are searching data for your request:

Forums and discussions:
Manuals and reference books:
Data from registers:
Wait the end of the search in all databases.
Upon completion, a link will appear to access the found materials.

While bumping through obscure corners of the Internet, I encountered the following image posted somewhere.

The horse anus is a marvel of evolutionary biology.

Like most mammals, rhythmic contractions of the bowels move the feces up to the end of the gut to be expelled.

What sets the horse anus apart is the bafflingly complex autonomic contractive motion of 4 muscular rings which function like sphinctoral guillotine. As the feces is squeezed out, the rings expand and the outermost ring is retracted into an interior skinfold resembling the human foreskin, leaving an interstital tissue fold to open air.

The two inner rings then contract, and push apart, severing the horse feces cleanly, allowing to drop free as the outer ring folds back through the interstital flap, creating a intrinsic wiping motion with the fourth ring as it contracts back into the horses rectum.

This advanced biological mechanism is so effective that many industrial companies have copied Nature's design for self-cleaning viscus liquid dispensers housed within complex machinery.

Quite interesting, but anyone who saw one, recognizes an imageboard post - probably the infamous 4chan, where each page bears the warning: "The stories and information posted here are artistic works of fiction and falsehood. Only a fool would take anything posted here as fact." Accordingly, I'm skeptical. So, a verification please?

Ministry of Agriculture, Food and Rural Affairs

Horses have the potential for high reproductive performance. With an understanding of basic reproductive science, breeders can be better positioned to achieve their goals.

This Factsheet presents information on basic anatomy, physiology and management techniques that can assist in improving reproductive performance in the mare.

Estrous Cycle

The estrous cycle in most mares starts to normalize in late April or early May until August - the normal breeding season for horses. During this time, the mare will have an estrous cycle of 21 days (±3 days). The estrous cycle is composed of two phases: the estrous phase (in heat) and the diestrous phase (out of heat). Estrus usually lasts for 6 days, but can be 4-10 days, depending on the mare. Diestrus is normally 15 days, but may vary from 12-18 days. From September through March, very few mares will cycle normally, so conception is more difficult to achieve during these months.

Ovulation, the release of the egg from the ovary, can occur at any time during the estrus phase. However, it normally occurs 24-48 hr before the end of the estrus period. Ideally, to maximize the chance of conception, breeding should occur within 12 hr of ovulation. Breeding or insemination of mares, starting on Day 2 or 3 of estrus and continuing every other day throughout the estrus, is a practical means of achieving satisfactory pregnancy rates.


The mare's first estrus phases of each year are often erratic and prolonged, during which time mares may be in heat for 20-30 days or more. During late March, April and May, most mares exhibit sexual receptivity, and from late April through August, most mares will cycle normally.

Few early estruses result in ovulation thus it is not recommended to breed mares during this time without rectal palpation of the ovaries to determine follicular development.

The primary environmental factor causing mares to cycle normally is increased hours of light (photoperiod). Artificial lighting can be used to induce mares to cycle earlier in the year.


The estrous cycle is controlled by hormones (Figure 1). Hormones are chemical substances created by the body that control various bodily functions. This section describes some of the hormones involved in mare reproduction.

Figure 1. The estrous cycle.

The pituitary gland is located at the base of the brain and produces follicle-stimulating hormone and luteinizing hormone. As spring approaches, the pituitary gland is stimulated by increased daylight to enhance follicle-stimulating hormone production. Follicle-stimulating hormone is released into the blood stream and travels to the ovaries to initiate development of a follicle containing an ovum. The developing follicle produces estrogens, which are released into the blood stream.

Estrogens have a number of functions in the body. When blood estrogen reaches a certain level, a surge of luteinizing hormone is released from the pituitary gland into the blood stream. Estrogens are responsible for the clinical signs of estrus and act on the oviducts, uterus and cervix to prepare the reproductive tract for pregnancy.

The surge of luteinizing hormone causes the follicle on the ovary to rupture, resulting in ovulation. As the follicle develops on the ovary, the ovum (egg) inside the follicle undergoes a number of changes to become capable of being fertilized by the sperm. The follicle contains a viscous fluid and when the follicular wall ruptures, this fluid flows out, carrying the ovum with it. The cavity left by the ruptured follicle becomes engorged with blood to form a corpus hemorrhagicum. The corpus hemorrhagicum luteinizes to form the corpus luteum, sometimes called the yellow body.

As the corpus luteum develops, it starts to produce progesterone, which influences the pituitary gland and reproductive tract. The feedback of progesterone via the blood stream inhibits the release of luteinizing hormone. Under the influence of progesterone, the mare will not show estrus. Progesterone function is to maintain the pregnancy by maintaining a uterine environment conducive to fetal development.

If the mare does not conceive, the corpus luteum remains functional for about 12-14 days. At this time, prostaglandin is released from the endometrium (inner lining of the uterus). Prostaglandin has a luteolytic effect - it acts on the corpus luteum via the bloodstream, causing it to regress. As the corpus luteum regresses, progesterone levels are reduced, resulting in the removal of the inhibition to luteinizing hormone secretion. The cycle starts over again.

If the mare conceives, hormonal activities are essentially the same as for the 12-14 days post-ovulation. Pregnancy recognition is stimulated by the action of the developing embryo migrating throughout the uterus this action inhibits prostaglandin release. The result is an antiluteolytic effect, so the corpus luteum remains functional, progesterone levels are maintained and the pregnancy is continued.

Somewhere between Days 25 and 30 of gestation, the corpus luteum starts to regress, resulting in declining blood progesterone levels. If the progesterone level were to continue to decrease, the pregnancy would be terminated. However, a compensatory system has evolved that is unique to the mare. Between the 25th and 36th day of gestation, a girdle-like band of special cells develops around the fetal sac. On about Day 37 of gestation, this band detaches from the fetal membranes and invades the endometrial wall where these cells undergo tremendous enlargement and structural change. These cells clump to form the endometrial cups that secrete the hormone equine chorionic gonadotropin. Equine chorionic gonadotropin reaches the ovaries via the blood stream, stimulating secondary follicular development and luteinization. The secondary corpus luteum produces progesterone, as does the primary corpus luteum to Day 130 to 150 of gestation. From about Day 80 of pregnancy to term, adequate progesterone levels are maintained by special areas of the uterus and fetal membranes, to sustain the pregnancy.

The pregnant mare foals (parturition) at 340 days ±20, post-breeding. Initiation of parturition is very complex and not completely understood, but the fetus probably plays a role in initiating the process. Mechanical stimuli occur from distension of the uterus, which brings about an increased sensitivity of the uterus to the hormones estrogen and oxytocin. At the end of pregnancy, the uterus becomes active and the cervix dilates. Oxytocin, released by the pituitary gland, causes the muscles of the uterus to contract and expel the fetus (foal).


Figures 2 and 3, respectively, depict sagittal and frontal views of the mare reproductive structures.

Figure 2. Sagittal view of the mare reproductive structures.

Figure 3. Frontal view of the mare reproductive structures.

Broad ligament - a tough layer of fibrous tissue, containing blood vessels and nerves that serve to suspend the majority of the reproductive tract in the abdomen.

Cervix - a structure of approximately 10 cm (4 in.) in length between the vagina and the uterus. It is the "door to the uterus" and serves to maintain a sterile environment in the uterus. It relaxes when the mare is in heat and closes when not in heat or pregnant.

Infundibulum (fimbria) - the "catcher's mitt" structure at the ovarian end of the oviduct that picks up the ovum from the ovary at ovulation and transports it down into the oviduct.

Ovary - the primary sex organ of the mare. The ovary produces the ovum (egg) to be fertilized and serves as an endocrine gland producing the hormones estrogen and progesterone.

Oviduct - a long, convoluted tube extending from the infundibulum to the end of the uterine horns. It serves to transport sperm and ova to the site of fertilization in the upper one-third of the oviduct. The fertilized ovum is then transported to the uterus.

Uterus - a large uterine body, just anterior to the cervix, and two relatively short uterine horns that terminate in the oviduct. The uterus is where the majority of embryonic development and nourishment takes place. It also produces hormones and is the receptacle where semen is deposited during natural breeding.

Vagina - part of the birth canal that lies in the pelvic girdle between the vulva and the cervix.

Vulva - the external opening of the urogenital tract. It is part of the birth canal, and the area where urine is voided.


The site of semen deposition in the mare is intra uterine (natural breeding) or the uterine body (artificial insemination). The muscular movements of the uterus and oviduct under the influence of estrogens are responsible for the migration of sperm to the oviduct.

When the follicle ruptures, it releases the ovum to be picked up by the fimbria (infundibulum). The fimbria funnels the ovum into the oviduct, where it comes in contact with the sperm. The union of the sperm and ovum forms the zygote, the beginning of an embryo. The embryo moves down the oviduct to the uterus. The time required to move the embryo from the site of fertilization into the uterus is about 6 days. By this time, the uterus has been under the influence of ovarian progesterone to create a suitable environment for fetal development and implantation.

Studies have shown that the embryo is relatively mobile within the uterus until Day 16 or 17, post-ovulation, because of the increased uterine tone, thickening of the uterine wall and enlargement of the vesicle. Movement throughout the uterus plays a role in the inhibition of the mare's estrous cycle.

Implantation occurs around Day 35 of gestation and placentation is initiated around Day 40 to Day 45. Up to this time, the fetal sac lies unattached in the lumen of the uterus.

Horses reach puberty between 12 and 18 months of age. It is therefore advisable to keep colts and fillies separate once they have reached 1 year of age. Even though young horses can reproduce, it is not advisable. Mares that are bred prior to maturity will require extra care and nutrition, especially during the period of lactation and last 3 months of pregnancy (due to the risk of dystocia), so that she and her foal will grow to their genetic potential.

Handle mares and performance test them prior to being bred, to assess their quality. If they perform well, the value of their foals increases.


The mare's body condition will influence her reproductive performance. Mares that are moderately fleshy (slight crease down the back, fat covering the outlines of the ribs, noticeable amounts of fat along the sides of neck and withers, and soft fat deposited around the tail head) can be expected to:

  • cycle earlier in the year
  • have fewer cycles per conception
  • have higher pregnancy rates
  • maintain pregnancy more easily than thin mares

Therefore, preparing a mare for breeding with a feeding program of sufficient, nutritionally balanced, high-quality feed is recommended.

To detect a pregnancy, a transrectal ultrasound is recommended as early as 12-15 days, post-breeding. Also, a veterinarian can conduct a foal-time test between Day 45 and Day 120 to confirm pregnancy. A foal-time test is a serological test that detects the presence of equine chorionic gonadotropin it does not guarantee that the mare is pregnant at the time of testing, but does indicate whether the mare was pregnant up to Day 37 of gestation. Knowing that a mare is not pregnant allows for planning additional breeding attempts.

Following recommended management practices and understanding the basic reproductive science of the mare will improve chances for reproductive health and success of the mare.

Interesting Insights from the Zonkey!

A hybrid animal like the zonkey is not only interesting, it encapsulates many biological concepts that are very important to understand!

Creating a Hybrid

Essentially, hybrids can even go on to become their own species if they inherit an even number of chromosomes (to ensure the success of meiosis) from relatively closely related species.

Many hybrids are not true species because they lack an ability to reproduce successfully. Many horse hybrids, like the zonkey, inherit an odd number of chromosomes – leading to massive complications during meiosis. Animals that are completely unrelated would be extremely unlikely of forming a hybrid simply because the proteins they encode have evolved from such different evolutionary paths.

Sterile Hybrids (Haldane’s Rule)

Evolutionary biologist J.B.S. Haldane first noted in 1922 that genetic hybrids are often inviable or sterile. Further, he noted that in most hybrids the heterogametic sex is more affected than the homogametic sex.

In mammals, males are the heterogametic sex because they carry both an X and Y chromosomes. Though male zonkeys are viable, they cannot reproduce and are totally sterile. This is why it is impossible to reproduce two zonkeys – only the female can reproduce and most are close to infertile.

The reason for sterile hybrids is simple – there is an odd number of chromosomes in a hybrid organism. To create a zonkey, you must combine a plains zebra (44 chromosomes) with a donkey (62 chromosomes). The result is an offspring with 53 chromosomes.

Since 53 divides unevenly, the results of meiosis are not balanced haploid cells. Instead, they are often inviable cells that cannot reproduce. Males (the heterogametic sex) tend to be completely sterile because they typically did not receive a full set of functional chromosomes from their parents.

Equine Hybrids

Donkeys and zebras are just one of the many hybrids that have been created in the with species in the Equus genus. Though species in the genus have varying numbers of chromosomes, they have evolved along very similar lines.

Biologists hypothesize that some speciation events occur when an error in the genome causes entire chromosomes to accidentally be copied or repeated. Though species as distinct as zebras and donkeys may look very different, they express a lot of the same proteins.

The same is true of almost every other hybrid equine breed including mules, hinnies, zorses, and zony breeds. While this sometimes produces infertility, there can be positive benefits. For example, mules are much stronger, more heat-tolerant, and live longer than the average horse. More research needs to be done to investigate the benefits of creating a zonkey!

Conclusion: Iridology is bunk

Iridology is an excellent example of pseudoscience in medicine, displaying many of the core features. It was invented by one individual based upon a single observation. It follows a pre-scientific notion of biology – the homunculus model. It lacks any basis in anatomy, physiology, or any other basic science. Its practitioners are mostly “alternative” practitioners who use the technique as a cold reading. And the research clearly shows that iridology has absolutely no effect – it does not provide any useful information at all.

Anyone using or promoting iridology is, therefore, a pseudoscientific practitioner. Any profession that endorses iridology is not science-based and should be looked upon with suspicion.

Guttural Pouches

Also known as: Auditory Tube Diverticulum


The guttural pouches are paired ventral diverticulae of the eustachian (auditory) tubes, formed by escape of mucosal lining of the tube through a relatively long ventral slit in the supporting cartilages. The auditory tube connect the nasal cavity and middle ear and the diverticulum dilates to form pouches which can have a capacity of 300-500ml in the domestic horse. The pouches are normally air filled.


The Guttural Pouch is located below the cranial cavity, towards the caudal end of the skull/wing of atlas. It is covered laterally by the Pterygoid muscles, parotid and mandibular glands. The floor lies mainly on the pharynx and beginning of the Oesophagus. The medial retropharyngeal lymph node lies between the pharynx and ventral wall of the pouches.

Right and left pouches are separated dorsomedially by rectus capitis ventralis and longus capitis muscles. Below this, by fused walls of the two pouches, the median septum is formed.

Each pouch is moulded to the stylohyoid muscle which divides the medial and lateral compartments, the medial compartment being approximately double the size of the lateral one and extends further caudally and ventrally.

The guttural pouch has close association with many major structures including several cranial nerves (glossopharyngeal, vagus, accessory, hypoglossal), the sympathetic trunk and the external and internal carotid arteries. The pouch directly covers the temporohyoid joint. The pouch has an extremely thin wall which is lined by respiratory epithelium which secretes mucus. This normally drains into the pharynx when the horse is grazing.

Several cranial nerves and arteries lie directly against the pouch as they pass to and from foramina in the caudal part of the skull (vessels within mucosal folds that indent the pouches):

Cranial nerves IX, X, XI, XII. Continuation of the sympathetic trunk beyond the cranial cervical ganglion. Internal carotid artery.

Cranial nerve VII - limited contact with the dorsal part of the compartment. External carotid artery crosses the lateral wall of the lateral compartment in its approach (as maxillary artery) to the atlas canal. The external maxillary vein is also visible.

Natural drainage of the pouch is throught the slit-like (pharyngeal) openings of the eustachian tube in the lateral wall of the nasopharynx. The connection opens when the horse swallows and grazing normally provides drainage. However, most of the pouch is ventral to his slit, and therefore drainage may be rather ineffective. If blocked, secretions accumulate and the pouch distends producing a palpable swelling.


The function of guttural pouches is largely unknown, however hypotheses have been put forward:

  1. It may influence internal carotid artery blood pressure. Air pressure varies with phase and forcefulness of respiration and the artery in the mucosal fold is exposed sufficiently to be affected.
  2. Cerebral blood cooling mechanism. Operates at times of physical stress/exercise, when core body temperature is raised. Vigorous respiration, cool air in guttural pouches, and the exposed artery all lead to cooling of the blood.



This form is only for prospective students who are not already enrolled at UNH. If you are a current UNH student and interested in this program, please reach out to the contact on this page.

Pericardial Disorders

Pericarditis is a disorder of the pericardium in which the pericardium becomes swollen or inflamed. This inflammation disrupts normal heart function. Pericarditis can be acute (happens suddenly and over quickly) or chronic (happens over a period of time and lasts for a long time). Some causes of pericarditis include bacterial or viral infections, cancer, kidney failure, certain medicines, and heart attack.

Pericardial effusion is a condition caused by the accumulation of large amounts of fluid between the pericardium and the heart. This condition can be caused by a number of other conditions that affect the pericardium, such as pericarditis.

Cardiac tamponade is pressure build up on the heart due to excessive fluid or blood build up in the pericardium. This excess pressure does not allow the heart ventricles to fully expand. As a result, cardiac output is lowered and blood supply to the body is insufficient. This condition is most commonly caused by hemorrhage due to penetration of the pericardium. The pericardium may become damaged as a result of severe trauma to the chest, a knife or gunshot wound, or accidental puncture during a surgical procedure. Other possible causes of cardiac tamponade include cancer, heart attack, pericarditis, radiation therapy, kidney failure, and lupus.

The Detox Scam: How to spot it, and how to avoid it

New Year, New You, right? 2014 is the year you’re finally going to get serious about your health. You’re winding down from a week (or more) of celebrations and parties. You’re pretty much recovered from New Year’s Eve by now. It’s time to make some resolutions. Conveniently, there is no shortage of solutions being advertised to absolve you of your sins while overhauling your body and soul for 2014: What you need to do is “detox”. You’ll see the detox kits at your local Whole Foods (or even your local pharmacy). Books, boxes or bottles, with some combination of “detox”, “cleanse” or “flush” in the product name. Supplements, tea, homeopathy, coffee enemas, ear candles, and footbaths all promise detoxification. The advertising suggests you’ll gain a renewed body and better health – it’s only seven days and $49.95 away. Or try to cleanse yourself with food alone: Dr. Oz is hyping his Holiday Detox plan. Bon Appetit is featuring their 2014 Food Lover’s Cleanse. Or what about that old standby, the “Master Cleanse”? It’s the New Year – wouldn’t a purification from your sins of 2013 be a good idea to start the year? After all, the local naturopath offers complete detoxification protocols, including vitamin drips and chelation. There must be something to it, right?

Wrong. “Detox” is a case of a legitimate medical term being turned into a marketing strategy – all designed to treat a nonexistent condition. In the setting of real medicine, detoxification means treatments for dangerous levels of drugs, alcohol, or poisons, like heavy metals. Detoxification treatments are medical procedures that are not casually selected from a menu of alternative health treatments, or pulled off the shelf in the pharmacy. Real detoxification is provided in hospitals when there are life-threatening circumstances. But then there are the “toxins” that alternative health providers claim to eliminate. This form of detoxification is simply the co-opting of a real term to give legitimacy to useless products and services, while confusing consumers into thinking they’re science-based. Evaluating any detox is simple: We need to understand the science of toxins, the nature of toxicity, and how detox rituals, kits, and programs claim to remove toxins. With this framework, it’s a simple matter to spot the pseudoscience and be a smarter consumer.

Premise one: Our bodies are accumulating toxins

There’s a reason we fall for the marketing of detoxification – we seem hardwired to believe we need it, perhaps related to our susceptibility to ideas of sympathetic magic. Purification rituals date back to the earliest reaches of recorded history. The idea that we’re somehow poisoning ourselves and we need to atone for our sins seems to be a part of human nature, which may explain why it’s still a part of most of the world’s religions. It’s not miasmas or perhaps sin that we’re as worried about today, however. As our knowledge of biology grew, these fears manifested as “autointoxication.” Clean out the bowels, went the theory, and you could cure any illness. Science led us to discard autointoxication by the 1900’s as we gained a better understanding of anatomy, physiology, and the true cause of disease. Despite the science, however, the idea persists among alternative practitioners. Today’s version of autointoxication argues that some combination of food additives, gluten, salt, meat, fluoride, prescription drugs, smog, vaccine ingredients, GMOs, and perhaps last night’s bottle of wine are causing a buildup of “toxins” in the body. But what is the actual “toxin” causing harm? It’s nothing more than a meaningless term that sounds scientific enough to be plausible. A uniform feature of detox treatments is the failure to name the specific toxins that these rituals and kits will remove. For example Renew Life promises you:

CleanseSMART is a 2 part, 30 day, advanced herbal cleansing program. It is formulated to stimulate the detoxification process of the body’s 7 channels of elimination: the liver, lungs, colon, kidneys, blood, skin, and lymphatic system. In today’s toxic world, cleansing and detoxification is a necessity. Toxins enter our body daily through the air we breathe, the food we eat, and the water we drink. Over time, these toxins build up and slowly start to affect our health in a negative way.

Through cleansing and detoxification, you enable your body to better process this toxic load. Reducing the toxic load in your body decreases the risk of developing chronic health problems, improves overall health and immune response, and can increase energy levels. CleanseSMART works to cleanse and detoxify the entire body, but with focus on the body’s two main detoxification pathways – the liver and the colon. CleanseSMART is essential for helping eliminate constipation and improving bowel health.

Note the vague language. Toxins are alluded to – but not named. It sounds somewhat plausible, but is non-specific. Note that even if you’re well (and presumably toxin free?) a detox is still recommended.

The colon remains ground zero for detox advocates. They argue that some sort of toxic sludge (sometimes called a mucoid plaque) is accumulating in the colon, making it a breeding ground for parasites, Candida (yeast) and other nastiness. Fortunately, science tells us otherwise: mucoid plaques and toxic sludge simply do not exist. It’s a made-up idea to sell detoxification treatments. Ask any gastroenterologist (who look inside colons for a living) if they’ve ever seen one. There isn’t a single case that’s been documented in the medical literature. Not one.

Premise two: Illness is the result of toxins

Marketing materials for detox treatments typically describe an array of symptoms and diseases linked to toxin buildup: A few that are general enough to apply to anyone (e.g., headache, fatigue, insomnia, hunger) with a few specifics to frighten you (cancer, etc.) Which toxins cause which disease is missing, and how the toxins cause the symptoms is never actually explained. Here again we see the contrast with real science. To establish that even a single chemical can cause disease requires a significant amount of research (i.e., the entire field of epidemiology). Despite the variety of toxins that are claimed to be causing your illness, marketing claims for detox treatments will uniformly fail to link specific toxins to specific symptoms or illnesses.

The reality is that our bodies are constantly being exposed to a huge variety of natural and synthetic chemicals. The presence of any chemical in the body, (natural or synthetic) does not mean that it is doing harm. Many naturally-derived substances can be exceptionally toxic, and consequently the human body has evolved a remarkable system of defenses and mechanisms to defend against, and remove unwanted substances. The skin, kidneys, lymphatic system, our gastrointestinal system, and most importantly, the liver make up our astoundingly complex and sophisticated intrinsic detoxification system. Importantly, the dose makes the poison – even water can be toxic (dilutional hyponatremia) when consumed in excessive amounts.

Advocates for detox typically describe the liver and kidney as acting like filters, where toxins are physically captured and retained. It’s argued that these organs to be cleaned out periodically, like you’d rinse out a sponge, or change the air filter in your car. But the reality is the kidney and liver don’t work this way. The liver performs a series of chemical reactions to convert toxic substances into ones that can be eliminated in bile, or the kidneys. The liver is self-cleansing – toxins don’t accumulate in it, and unless you have documented liver disease, it generally functions without any problem. The kidney excretes waste products into the urine – otherwise the substance stays in the blood. To argue that either organ need a “cleanse” is to demonstrate a profound ignorance of human physiology, metabolism, and toxicology.

Premise three: Detox treatments remove toxins

A search of the medical literature for clinical studies of detox kits provides the following result:

There is no credible evidence to demonstrate that detox kits do anything at all. They have not been shown to remove remove “toxins” or offer any health benefits. The same can be said for quackery like coffee enemas – there is no credible evidence to support claims that coffee enemas help the body to “detoxify” compounds, or help the liver function more effectively. Vitamin injections are another treatment that fail to offer meaningful benefits to consumers, and have no beneficial effect on the ability of your liver or kidneys to work effectively. Chelation injections are touted as a cure-all for all kinds of illnesses, but unlike real chelation that’s administered in hospitals for real cases of poisoning, naturopath chelation is not science-based and doesn’t seem to do much of anything.

Can Detoxing be harmful?

If they provide no benefit, is there the potential for detox treatments to harm?

When it comes to simple dietary changes, there’s little evidence of harm. Eating more quinoa and kale, and less processed and refined foods is reasonable dietary advice for everyone. Homeopathic “detox” is also likely safe – with no active ingredients, homeopathy is an elaborate placebo system. As you get into more unorthodox detox treatments that actually contain active ingredients, it’s clear that some approaches are demonstrably risky. Coffee enemas are considered unsafe and should be avoided. Harms such as septicemia (bacteria in the bloodstream), rectal perforation, and electrolyte abnormalities have been reported. Even deaths. Vitamin injections don’t seem as risky, as long as you trust the sterile technique of your alternative provider. However, given some naturopaths seem to be willing to inject products intended for oral use, you might want to think carefully about taking a vitamin injection or chelation treatment, especially when there’s no reasonable expectation of any benefit.

What about the detox kits? Contents vary, but typically contain two categories of ingredients:

  1. A liver “booster” – typically milk thistle (Silibum marianum). If the liver can’t be wrung out and rejuvenated, can it be boosted to do a better job? Milk thistle is the most popular product purported to “boost” the liver’s effectiveness. There are no published studies that demonstrate milk thistle has a detoxifying effect on the liver. Milk thistle has been studied in patients with alcoholic liver disease, and in patients with hepatitis B or C, and it has not been found to exhibit any meaningful effects. There is no evidence to suggest that consuming milk thistle will cleanse you of unnamed “toxins”.
  2. A laxative – Typically magnesium hydroxide, senna, rhubarb, cascara, etc. Laxatives are the ingredients in detox kits that give you the effect you can see (and feel). However, these ingredients can cause dehydration and electrolyte imbalances if not used carefully. Regular use of stimulant laxatives, like senna and cascara, are ill-advised for most healthy adults due to the risk of dependence and electrolyte depletion. They’re among the most potent laxatives, usually used for short periods to alleviate significant constipation or to clear out your bowels before a medical procedure. With regular use, your bowel can grow accustomed to the effects of laxatives which may result in constipation once you stop using them. It’s a perfect case of the treatment causing the illness: After the detox, you get could conceivably become constipated: Time for another detox!

Side effects can continue once a detox ends. Some people experience post-detox effects like nausea and diarrhea. Advocate call these “cleansing reactions” and will assure you it’s “toxins leaving the body”. A more plausible, science-based explanation is that this is a consequence of restarting the digestion process after a period of catharsis, where, depending on the extent and duration of fasting, little to no digestion occurred, and the normal gastrointestinal flora may have been severely disrupted. It’s the same effect seen in hospitalized patients who have difficulty initially digesting food after being fed intravenously. The detox ingredients, and resulting catharsis, may irritate the colon to such an extent that it may take time to return to normal.

Immediate weight loss is not uncommon after a detox, especially one that involves a laxative. Unfortunately this is usually due to losses in water and possibly muscle tissue, depending on the how disruptive the detox was to normal body function Regardless of the weight loss, the body will move back to its pre-detox weight over time if diet and activity levels remain the same.


Any product or service with the words “detox” or “cleanse” in the name is only truly effective at cleansing your wallet of cash. Alternative medicine’s ideas of detoxification and cleansing have no basis in reality. There’s no published evidence to suggest that detox treatments, kits or rituals have any effect on our body’s ability to eliminate waste products effectively. They do have the ability to harm however – not only direct effects, like coffee enemas and purgatives, but the broader distraction away from the reality of how the body actually works and what we need to do to keep it healthy. “Detox” focuses attention on irrelevant issues, and gives consumers the impression that they can undo lifestyle decisions with quick fixes. Improved health isn’t found in a box of herbs, a bottle of homeopathy, or a bag of coffee pushed into your rectum. The lifestyle implications of a poor diet, lack of exercise, smoking, lack of sleep, and alcohol or drug use cannot simply be flushed or purged away. Our kidneys and liver don’t need a detox treatment. If anyone suggests a detox or cleanse to you, you’d do well to ignore the suggestion, and question any other health advice they may offer.

Horse Terms Relating to Training

Green - An un-broke horse

Green broke - A horse with very little training

Green horn - A person unfamiliar with horses

Seasoned - A horse with years of experience under saddle

Halter broke - Not yet broke to ride

Started - Has had a saddle on a few times and is in early training

Prospect - A horse with potential to do well for a specific sport 

Finished - A horse that has been trained sufficiently for riding or to use in a particular way 

Outlaw - A 'problem' horse that is un-broken or unsuitable to ride

To 'pony' - The act of leading one horse while riding another

To 'sack out' (desensitizing) - The act of teaching a horse not to be afraid of things

Lead - Refers to the leading leg of a horse when running or turning. One front leg will move out first and reach farther than the other. That is the lead leg

Flying Lead Change - The horse changes lead at the riders command mid-run

Lounge - The act of moving a horse about in circles around the handler

Plow reins - A horse that turns when you pull the rein to the left or right

Neck reins - The horse will turn left or right with the mere pressure of the rein on the neck. They move away from the rein that is touching the skin

Leg queue - A signal given to the horse with the riders leg

Works 'off the leg' - A horse that responds well to leg queue's

Cutting Horse - A horse trained to work cattle, cut one from the herd

A Header - The horse ridden by the rider that ropes the calf's head

A Heeler - The horse ridden by the rider that ropes the calf's back feet

A Roping horse - A horse trained to work independently and keep the rope taught while the rider jumps off to hog tie the calf

A Hunter/Jumper - A horse trained to go over jumps

A Dressage Horse - A horse trained in the classical advanced style of English horsemanship

Grade horse (half breed) - Mixed breed or unknown heritage

Papered (registered) - A horse of known breeding that is registered with a recognized horse association

Hack - An English term used to describe a pleasure horse

OTTB - An off the track Thoroughbred

Seat - Proper sitting position while in the saddle

Soft hands - A rider that is gentle on the horses mouth with the reins

Collected - A horse in motion that has been brought into perfect balance by the rider and is ready to move in any direction at the riders command

Roll back - When a horse sits back and spins 180 º  turn on his hind feet and heads the opposite direction. Often done a high speeds

The Basics of Equine Nutrition

Horses are non-ruminant herbivores (hind-gut fermentors). Their small stomach only has a capacity of 2 to 4 gallons for an average-sized 1000 lb. horse. This limits the amount of feed a horse can take in at one time. Equids have evolved as grazers that spend about 16 hours a day grazing pasture grasses. The stomach serves to secrete hydrochloric acid (HCl) and pepsin to begin the breakdown of food that enters the stomach. Horses are unable to regurgitate food, so if they overeat or eat something poisonous vomiting is not an option.

Horses are also unique in that they do not have a gall bladder. This makes high fat diets hard to digest and utilize. Horses can digest up to 20 % fat in their diet, but it takes a span of 3 to 4 weeks for them to adjust. Normal horse rations contain only 3 to 4 % fat.

The horse’s small intestine is 50 to 70 feet long and holds 10 to 23 gallons. Most of the nutrients (protein, some carbohydrates and fat) are digested in the small intestine. Most of the vitamins and minerals are also absorbed here.

Most liquids are passed to the cecum, which is 3 to 4 feet long and holds 7 to 8 gallons. Detoxification of toxic substances occurs in the cecum. It also contains bacteria and protozoa that pass the small intestine to digest fiber and any soluble carbohydrates.

Photo & Diagram: C. Williams

The large colon, small colon, and rectum make up the large intestine. The large colon is 10 to 12 feet long, and holds 14 to 16 gallons. It consists of four parts: right ventral colon, sternal flexure to left ventral colon, pelvic flexure to left dorsal colon, and diaphragmatic flexure to the right dorsal colon. The sternal and diaphragmatic flexures are a common place for impaction. The small colon leads to the rectum. It is 10 feet long and holds only 5 gallons of material.

Horses require six main classes of nutrients to survive they include water, fats, carbohydrates, protein, vitamins,and minerals.

Water is the MOST IMPORTANT nutrient horses can’t live long without it! Always make sure there is an adequate, clean supply of water. Horses generally drink about 2 quarts of water for every pound of hay they consume. In high temperature, hard work, or for the lactating mare the water requirement may be 3 to 4 times the normal consumption.

Signs that your horse may be water deficient include decreased feed intake and physical activity, and signs of dehydration like dry mucous membranes in the mouth, dry feces, and decreased capillary refill time. Possible causes of water deficiencies include no water source, low water palatability, or accessibility (frozen or receiving or contaminated), or illness.

Energy isn’t one of the six nutrients because the horse cannot physically consume energy, however, it is a requirement for sustaining life. The most dense source of energy is fat (almost three times more than carbohydrates or proteins) however, carbohydrates in the forms of fermentable fiber or starch are the most common source. Horses exercising, growing, pregnant in late gestation or early lactation need increased energy in their diet.

Signs of energy deficiency include weight loss, decreased physical activity, milk production, and growth rate. However, feeding a diet too high in energy can cause obesity increasing the risk of colic, laminitis, and contribute to increased sweat loss and exercise intolerance.

Fat can be added to a feed to increase the energy density of the diet. Fat has 9 Mcal/kg of energy, which is three-times that of any grain or carbohydrate source. Fat is normally found at 2 to 6% in most premixed feeds however, some higher fat feeds will contain 10 to 12% fat. See Fat Supplements section for more.

Carbohydrates are the main energy source used in most feeds. The main building block of carbohydrates is glucose. Soluble carbohydrates such as starches and sugars are readily broken down to glucose in the small intestine and absorbed. Insoluble carbohydrates such as fiber (cellulose) bypass enzymatic digestion and must be fermented by microbes in the large intestine to release their energy sources, the volatile fatty acids. Soluble carbohydrates are found in nearly every feed source corn has the highest amount, then barley and oats. Forages normally have only 6 to 8% starch but under certain conditions can have up to 30%. Sudden ingestion of large amounts of starch or high sugar feeds can cause colic or laminitis.

Protein is used in muscle development during growth or exercise. The main building blocks of protein are amino acids. Soybean meal and alfalfa are good sources of protein that can be easily added to the diet. Second and third cutting alfalfa can be 25 to 30% protein and can greatly impact the total dietary protein. Most adult horses only require 8 to 10% protein in the ration however, higher protein is important for lactating mares and young growing foals.

Signs of protein deficiency include a rough or coarse hair coat, weight loss, and reduced growth, milk production, and performance. Excess protein can result in increased water intake and urination, and increased sweat losses during exercise, which in turn lead to dehydration and electrolyte imbalances.

Vitamins are fat-soluble (vitamin A, D, E, and K), or water-soluble (vitamin C, and B-complex). Horses at maintenance usually have more than adequate amounts of vitamins in their diet if they are receiving fresh green forage and/or premixed rations. Some cases where a horse would need a vitamin supplement include when feeding a high-grain diet, or low-quality hay, if a horse is under stress (traveling, showing, racing, etc.), prolonged strenuous activity, or not eating well (sick, after surgery, etc.).

Most of the vitamins are found in green, leafy forages. Vitamin D is obtained from sunlight, so only horses that are stalled for 24 hours a day need a supplement with vitamin D. Vitamin E is found in fresh green forages, however, the amount decreases with plant maturity and is destroyed during long term storage. Horses that are under heavy exercise or under increased levels of stress also may benefit from vitamin E supplementation. Vitamin K and B-complex are produced by the gut microbes. Vitamin C is found in fresh vegetables and fruits, and produced naturally by the liver. None of these are usually required in a horse’s diet. Severely stressed horses, however, may benefit from B-complex and vitamin C supplements during the period of stress.

Minerals are required for maintenance of body structure, fluid balance in cells (electrolytes), nerve conduction, and muscle contraction. Only small amounts of the macro-minerals such as calcium, phosphorus, sodium, potassium, chloride, magnesium, and sulfur are needed daily.

Calcium and phosphorus are needed in a specific ratio ideally 2:1, but never less than 1:1. Alfalfa alone can exceed a Ca:P ratio of 6:1. Sweating depletes sodium, potassium, and chloride from the horse’s system, therefore, supplementation with electrolytes may be helpful for horses that sweat a lot. Normally, if adult horses are consuming fresh green pasture and/or a premixed ration, they will receive proper amounts of minerals in their diet, with the exception of sodium chloride (salt), which should always be available. Young horses may need added calcium, phosphorus, copper, and zinc during the first year or two of life.

Forages are classified as legumes or grasses. The nutrients in the forage vary greatly with maturity of the grasses, fertilization, management, and environmental conditions. In order to determine the nutrient content in forage it is best to take samples and get them analyzed by a forage testing lab (contact your local County Extension Office for testing information or see the fact sheet, FS714, Analysis of Feeds and Forages for Horses).

Legumes are usually higher in protein, calcium, and energy than grasses. They have more leaves than grasses and require optimal growth conditions (warm weather and good soil) to produce the best nutrients. Some legumes include clover and alfalfa. Some commonly used grasses include orchard grass, timothy, bluegrass, and fescue.

Hay is forage that has been harvested, dried, and baled before feeding to horses. Legume hay can contain 2 to 3 times more protein and calcium than grass hay. However, it is usually more costly. Common grass hays include timothy, brome and orchard grass. They have fine stems, seed heads and longer leaves than legumes. They are most nutritious when cut earlier in their growth stage. Maturity at harvest is key to quality. Second cut grass hays average 16 to 20% protein.

Appearance can be a good indicator of the amount of nutrients in the hay, however, color should not be used as sole indicator. Moldy or dusty hay should not be fed to horses. For more information see Table 1.

Table 1. Evaluating Hay Quality

Low moisture content (12 to 18%).

Sweet smelling, like newly cut grass.

Grass hays before seed heads mature and alfalfa cut early in bloom.

Free from weeds, poisonous plants, trash, or foreign objects.

Damp. Too much moisture causes mold.

Brown, yellow or weathered in color. Gray or black indicates mold.

Musty, moldy or fermented odor.

Dusty and moldy hay is unacceptable.

Cut late in maturity. Mature seed heads with grass hay or alfalfa cut late in bloom.

High weed content, poisonous plants, or animal carcasses in hay bales.

Oats are the most popular grain for horses. Oats have a lower digestible energy value and higher fiber content than most other grains. They are also more palatable and digestible for horses than other grains however, they can be expensive.

Corn is the second most palatable grain for horses. It provides twice as much digestible energy as an equal volume of oats and is low in fiber. Because it is so energy dense it is easy to over feed corn, causing obesity. Moldy corn should never be fed—it is lethal to horses.

Sorghum (Milo) is a small hard kernel that needs to be processed (steam flaked, crushed, etc.) for efficient digestion and utilization by the horse. It is not palatable when used as a grain on its own, however, it can be used in grain mixes. Like corn, sorghum is high in digestible energy and low in fiber.

Barley also has hard hulls that should be processed to allow easier digestibility. It has moderate fiber and energy content, and can be a nutritious and palatable feed for horses.

Wheat is generally not used as a feedstuff because of its high cost. Its small hard kernels should be processed for horses to digest. Wheat is higher in energy than corn and best used in a grain mix because of its low palatability.

Protein Supplements

Soybean meal is the most common protein supplement, which averages around 44% crude protein. The protein in soybean meal is usually a high-quality protein with the proper ratio of dietary essential amino acids.

Cottonseed meal (48% crude protein) and peanut meal (53% crude protein) are not as common for horses as soybean meal.

Brewer’s grains (the mash removed from the malt when making beer) are a byproduct of the brewing industry. It is nutritious and palatable with about 25% crude protein and is also high in fat (13%) and B vitamins.

Fat Supplements

Vegetable oil is the most commonly used fat source in horse feeds. If adding the oil supplement as a top dress to feed start with ¼ cup/feeding and increase to no more than 2 cups/day over the course of 2 weeks for the average size horse (1000 lbs.).

Rice bran is a newer fat supplement on the market. It is distributed by some commercial feed dealers. It consists of about 20% crude fat, giving it an energy content of 2.9 Mcal/kg.

Forage is the base! Always try to feed the most forage possible then add concentrate.

Feed at a rate of 1.5 to 2% of the horse’s body weight (1000 lb. horse = 20 lbs.).

Feed by weight not volume!
** A 1 lb. scoop of Oats does not equal 1 lb. of Corn**

Stomachs are small so concentrates, if used, should be fed twice a day if not more with no more than 0.5% body weight per feeding.

To maintain body weight, most horses need only good forage, water, and a mineral block.

Store feed properly: it should be kept free of mold, rodents, or contamination.

Keep Ca:P ratios around 2 parts Ca to 1 part P.

Feed on a set schedule (horses are creatures of habit and are easily upset by changes in routine).

Change feeds gradually (horses’ stomachs cannot cope with drastic changes in feed could cause colic).

When work or exercise decreases, decrease the grain.

Be aware of the pecking order in your horse’s pen— are they getting their feed?

Examine teeth at least once a year to make sure they are able to chew feed.

References and Supplemental Reading

Lewis, L.D. 1995. Feeding and Care of the Horse (2 nd edition). Williams & Wilkins, Philadelphia, PA.

National Research Council. 1989. Nutrient Require­ments of Horses. National Academy Press, Washington, DC.

Watch the video: Equine Anatomy on a LIve Painted Horse (June 2022).