What is Equine Iridology

By Ellen Collinson, Dip.Ir., M.G.N.I. Equine Iridologist & Herbalist

Iridology is a centuries old scientific study/analysis of patterns and structures in the iris. A fantastic  non invasive and painless method enabling a trained person to recognise root causes of temperament, behavioural, health or performance issues. In the present we can see inherited and congenital strengths and weaknesses, pathological changes to the fibres of the Iris; conditions and inherited weaknesses, site of over activity, irritation, inflammation, degeneration of tissues and organs and toxic accumulation. The likelihood of conditions / problems manifesting before they develop into more serious cases or diseases. Old injuries, scarring, accidents, traumas, which could trigger future problems can also be seen. The organs we commonly see affected are the liver and kidneys due to modern regime and feed. If the liver or kidneys are malfunctioning this hugely affects the function of the other organs and can lead to a huge scenario of issues like indigestion, loss of appetite, or eating well but not gaining weight,, not absorbing nutrients efficiently, diabetes, cholesterol problems, hormone imbalances affecting mares, stallions and breeding and also muscle efficiency / tying up, behavioural problems, mood swings, and many more variations and scenarios.

The iris is divided into certain areas, like the face of a clock. Genetic markings passed from parents to offspring give an overall blueprint of the constitution, and can point out weaknesses often several years before symptoms or discomfort become apparent. The iris is made up of connective tissue containing approximately 28,0000 nerve endings, all of which are connected to the brain, the brain receives continual information regarding the organs and then records this information in the iris markings. 

Many illnesses are simply symptoms of an organ malfunction, iridology can reveal the root cause of the illness so that the right treatment is easier and more effective. Professional iridologists agree that acute, sub-acute, chronic and degenerative conditions of the body are all reflected in the iris. 

Although iridology is a recognised tool of diagnosis on humans, it is not widely known or practised on horses. However, there was a man called Syd Mercer who lived in England and used to diagnose through the eye. He was taught by a veterinarian called Stephenson during the first world war, after the war Mercer helped a lot of horses to win races, including Barona to win two Scottish Nationals and Rheingold to win the Arc de Triomphe. 

Good eye

Conventional X-rays or blood tests, scopes and scans only show up a break/fracture, disease/virus; they will not show up an organ that is merely weak, under stress or malfunctioning.

Bad eye

Apart from discovering what is wrong with your horse or pony, Iridology can be of assistance in the buying and or training of high performance horses, i.e. racing or eventing or endurance riding, as you would be able to tell which horses had old injuries, or had inherited temperament issues or an inherited or genetic weakness. This information can not be detected by a conventional veterinary examination, which can only tell you if the horse is sound in wind, heart and limb, on the day.

For example, inherited kidney weakness is one of the main things that will show up clearly in the eye and horses who have this weakness are prone to tying up and also the “sore back” or “cold back” syndrome.

The digestive ring will indicate whether the system is toxic, acidic, extended or whether there are ulcers and will also show up parasitic problems. It has been demonstrated that there is a direct relationship between parts of the colon and a corresponding reflex area of the body: in other words if the nerve wreath is pointing to a particular area, i.e., the liver, it will indicate the first signs that the liver is starting to come under stress. Any horse showing a problem in the digestive ring will be prone to other complaints and be unable to do their job properly.

Read a couple of examples of testimonials

Four years ago when Faith my friend and Iridologist saved my life, I began researching Equine Iridology.  It was non existent in the states.  Since then there are at least checking 100 Equine Iridologist in the states, all on the other side of the Mississippi.  Most of them trained by a woman in California who created her own charts etc. and no where near the background and education you carry,  there are also many fly by night courses that have suddenly popped up.

I am sure there may be some starting to pop up, but as far as I know I am the only (almost) Equine Iridologist on the East Coast.  I have a great deal of Education in human anatomy and biology, but of course turning it to the Eques world.  My next step as well as continuing to study Iridology is to become certified or licensed as an Equine Compounding Herbalist, to continue studying Equine anatomy and physiology.  To eventually teach, to really teach.  I guess my long trip around the mountain to get to the point…with my being the only Equine Iridologist (almost) this side of the states, there is room and need for a truly and highly educated Ellen Collinson here.  I most certainly desire to be a continued student of Ellen Collinson, to in years to come to teach others to continue on the legacy you have started.  I have done my homework!  I have done the research.  This was my shot and chance, and I studied and researched for a long time.  Money was in very, very short supply, and I had to be careful.  You are the best in the world, and that is why I went with studying under you, the real deal.  The equine world needs you to continue on.  If I am really lucky, before I leave this world, I might reach to a tiny percentage of the level you have attained.  You are the Equine worlds Dr. Jensen.

Your the best, as I said I did my homework!  Not only that, but I can tell you are kind, and your first love is to help horses, and help their people help their horses.  Greed is not at the core of your heart, but love.

Veryl Williams

Bridget astonishes the dentist!!
Bridget Bersford Wright has come up trumps again, she went to see a dressage horse about 3 weeks ago and in her own words. “I told the owner several things including that he had a tooth problem on the right hand side”.

Two weeks later she rang me to say, “Do you remember telling me about the tooth problem? She then said that the dentist had been about 3 weeks previous to my visit, but the horse was being a bit funny to the bit. So she called the dentist back out again. The Dentist found that the horse had broken a tooth, on the right hand side, and that there was a pointy bit of tooth that was causing a problem. The dentist sorted it out. When the owner told the dentist what I had said, the dentist said, “How the hell can anyone tell the horse has a bad tooth just by looking in his eyes?” She took my number, but I haven’t heard from her yet!!

Bridget Beresford Wright
When Taylor Denness, 14 years old scored her first elementary win with 72.41% on her 6 year old 16.2 Negro gelding Amaro O.

“We discovered, thanks to Bridget Beresford Wright, who came an gave an Iridology assessment on ‘Timmy’ that he suffered from a sugar intolerance, so on Bridget’s advice about the ‘oat diet’ we have started to feed him straights. Today, for the first time at a show he had energy without being uncontrollable, now when he drops the contact I can use my legs without feeling he will explode”

Mary Henley-Smith
I was introduced to Iridology by one of Ellen’s trained and qualified Iridologists in 2008 when I was rehabilitating ex-racehorses and re-training them for another career in life. I was instantly fascinated by how much this subject could tell me about the horses in my care and knew that I immediately needed to find out more, I contacted Ellen Collinson and enrolled on the course. The course is very well structured and teaches you step by step how to understand what is there showing in the horses eye, and reveals how much you can find out about your horse in order to help to heal and rehabilitate the animal, and avoid future problems. It still amazes me now how incredibly consistent and accurate the information can be and it helps me every day with these horses in my job to prepare them mentally and physically for a different job in life. Due to my busy schedule it took me a year to finish the course. It was a great learning curve and it is now helping me to give these horses and others a much better chance at living a healthy and fulfilling career. Some go on to be dressage horses, some long distance/pleasure rides, some event horses and many just very pleasurable hacks but all leave here very healthy as a result of what I can discover through the Iridology and I often wonder where I would be if I had not had the privilege of being introduced to such a worth while and fascinating subject. It is totally non-intrusive and one of the best diagnostic tools I have ever discovered. It helps me every day to do my job here better.

Mary Henley-Smith BHSII & BHS.SM
Yard Manager at
Moorcroft Racehorse Welfare Centre

Dear Ellen,
I feel I must email you with regard to your work on my mare Dolly. The mare had been put on the back burner for over a year due to injury and I must admit I was somewhat in denial of whether she ever would be any kind of a riding horse again, but fate brought you to me and after your findings by what appeared to me a very unusual way of diagnosis (iridology) and the fact that you prefered not to know the horses history I can honestly say for me was mind blowing, not only did you locate the sight of injury but also where a secondary condition was manifesting and was compounding the initial problem, you assured me that although the injury would never go there was actually no damage to the joint, which as you now know was my major concern. You as you may recall advised some osteopathic work on the secondary back condition and assured me that Dolly was in fact otherwise very well, This and this is where I thank you most, gave me the confidence to face the fact that Dolly would never be certifiably sound but that she could still make a perfectly good hack/fun horse. So just to let you know for your records the osteopath came and confirmed that the stifle joint was actually fine although would always be somewhat compromised by the actual injury. She also found and confirmed the secondary back condition that through her manipulations and my continued suppling excersises has given me back my riding horse and one that I am confident to push. So thanks again Ellen and I am happy to promote your work to anyone, especially to those of us that live in rural France and have little or no access to modern diagnostic tools short of travelling the hundreds of kilometres to the nearest horse hospital. All that information by looking in a horse’s eye, I for one am impressed.

Yours Karen Osborne
Fressanges 87160 Arnac La Poste




Why do we need to worm horses?

For years, all the books have told us that it is essential to do a worming treatment every 3 months. This is often by panicking horse owners into fears of what will happen if they don’t: the risk of ill-thrift, dull coats, weight loss and, the worst case scenario, colic.

As is pretty obvious, worms will compete with horses for their food and, in some cases, suck the blood from the horse’s digestive tract, causing damage that will be permanent and can affect the horse secreting the chemicals necessary for it to digest its food properly. In extreme cases, the worms can be so large that they can actually block the digestive tract, causing the horse to become seriously ill or even die. This can be seen in foals or yearlings.

Blanket worming has many drawbacks as it is not an exact science. Many of the household brand wormers work only for one type of worm and not for others. As we will see later, there are few ways of clearing parasites with a single product. Today we are advised to change our products each time, but how many people realise that many wormers have the same ingredients and are just being sold under a different name? It is essential to not only change the brand but to make sure you are changing the drug. Is this the reason we are often told about parasites becoming immune to current worming products and then breeding more immune parasites?

In the wild, horses are found to have less worms than in a domesticated environment, especially where horses are kept in small confined paddocks. If paddocks are kept clean, as we will see later, that can help cut down the problem. The domestication of horses has meant that they are kept in much closer proximity to each other than they would be in the wild and we find that the worm burdens are much higher.

Types of Worm found to be affecting horses

In a paper written by Don Hudson, Dale Grotelueschen and Duane Rice it is reported that most cases of colic can be put down to parasites. The larvae of bloodworms, from the Strongyles family, cause massive damage to blood vessels. They also reported that as much as 50% of all deaths in horses can be related to internal parasites.

To understand equine parasites properly, it is necessary to remember that there are five major internal parasites. Many horsemen realise that horses get parasites, or worms, but do not tend to look at the subject in any more depth; they will use the same chemicals to remedy the problem year in year out and wonder why their horses are still carrying parasites. The five groups include large and small strongyles, ascarids, bots and pinworms.

Most parasitical worms are passed between horses, via the droppings. Horses that graze near areas where there are droppings can involuntarily pick up infected eggs whilst eating. These eggs, once in the next horse will hatch, grow into adults and then lay eggs and the process starts all over again … This is a very simplistic description, but of course there is great variety from species to species.

Strongyles (Bloodworms)

The strongyles, or bloodworms, are the most dangerous of the parasites that infest horses and they are common in horses of all ages, barring foals. There are 50 different species of these bloodworms which tend to inhabit the large intestine and they are divided into two groups, large and small strongyles. The three main species of the large species are: Strongylus vulgaris, Strongylus equinus andStronggylus edenatus. As larvae, they travel to the heart, liver and lungs using the blood vessels as transport, destroying a lot of healthy tissue and leaving scar tissue in their wake. Horses that are carrying bloodworms will deposit the eggs in their dung most of the time. If a grazing horse eats these larvae, they can remain dormant in the intestinal lining for long periods of time. Large amounts of larvae can build up here and eventually they will erupt through the intestinal wall. This can be very damaging to the horse in question. These larvae eventually develop into adults, who in turn lay new eggs (often thousands at a time) and the cycle is repeated. It is more important to control these worms in adult horses than in young animals.

The small strongyle can often be more of a problem than their larger cousins as there are around 40 species and in many cases they are getting more and more immune to conventional chemical wormers. When they get through the gut wall, this is often the cause of colic. Another factor to be aware of is the effect of a bout of chemical de-worming on these parasites because it can act as a trigger for a large number of larvae to emerge through the intestinal wall. This can happen very quickly, within seven to ten days, and in extreme cases this can cause the horse diarrhoea, muscle wasting or weakness and even serious bouts of colic or, worse still, the death of the animal. The large strongyles are easier to control than the smaller variety.

Chemical de-wormers have little effect in breaking this cycle and many of these small strongyles are becoming very resistant to certain classes of anthelmintics. Another point to consider is that the adult worms are less lethal to horses than when they are at the larval stage. With these parasites, the ideal is not to contaminate the environment with them. Once larvae are infecting land, the only way to control them is effective land management, i.e. removing droppings, keeping horses off the land and the hope of warm weather. Another important consideration, if it is practical, is to rotate the animals that use the land. Parasites that effect horses tend not to effect sheep or cattle and vise-versa.

One other effective method is the herbal approach to parasite expulsion that does not cause the same problems that are associated with chemical worming. This method will be discussed later.

It is a fact that not all horses within a herd will be highly contaminated, indeed it is often just a few offenders that infect the rest. One way to help deal with this problem is to carry out faecal egg counts and thus identify the culprits.

Large Roundworms (Parascaris equorum)

Unlike the strongyles, these parasites mainly affect foals and young horses and tend not to be a problem for older animals. Their eggs can remain dormant in the soil for up to 10 years before they are swallowed by horses whilst grazing but once in the animal’s intestine they will start to hatch. Once hatched in the gut system, they move through the walls and into the veins. Their journey takes them up to the lungs, where they go from the alveoli (or air sacks) through the bronchioles until they reach the trachea. Once they are at the back of the throat, the young horse will then swallow them, returning them to the small intestine where they will grow into adults. These adults can grow as large as 50cm long before they lay their own eggs which are in turn excreted in the droppings.

Most foals will be exposed to roundworm eggs and any parasite control programme must be targeting this species when managing immature horses. Good control should look at both killing the worms as well as to stopping them maturing; thus stopping the egg production and breaking the cycle. A word of caution though: there have been reports from the USA and Canada showing that conventional wormers used for this purpose are starting to encounter major resistance from the worms. This situation is likely to be the same in the UK and Europe.

Bots (Gasterophilus intestinalis)

The bot fly looks similar to a honey bee and is often seen singly or in groups around horses. In the summer, horses can be seen rushing around their paddocks trying to avoid these flies. These are usually females looking to deposit their eggs on the animals’ legs. The flies tend to be striped and the eggs a yellow colour.

The legs are not the final resting place for these eggs and their mission is to get into the horse’s mouth. Within five days, the eggs are ready to hatch; and this happens when the temperature rises due to horses’ faces getting near them as horses use their muzzles to try and stop the itching. The larvae then enter the horse’s mouth and they burrow into its tongue. The next stage of the process is when they change colour to red, due to production of haemoglobin, which is necessary due to the low oxygen levels in the horse’s tongue. From here, they migrate to the stomach of the horse at which point they become a fully grown bot. They will remain in the stomach for as long as 12 months where there is sufficient oxygen for them to survive.

By late spring, these bots will get excreted by the horse in its droppings and the bots pupate and become adult flies, a process that takes around three weeks, before the cycle starts again.

The early stages of the larvae’s development can have an impact on the host’s health, especially relating to their gums and teeth as well as within their intestines.

Tapeworms (Anoplocephala perfoliata)

The last group of parasitical worms that needs to be discussed is the equine tapeworm, so called as it resembles a measuring tape and is short and triangular and comparatively smaller than those found in cats, dogs and humans. The worm is made up of segments (proglottid) that are like carriages on a railway train. At any point, a segment or segments can break off without killing the worm. For years it was believed that tapeworms were not common in horses and that was because the proglottids tend to dissolve in the large intestine and are rarely seen in the horses’ faeces. It had also been thought that these tapeworms caused little harm to horses, but it is now known that they are responsible for certain types of severe colic.

Tapeworms contain both male and female reproductive organs and, as with other parasitical worms, they produce eggs, but unlike other parasites, they don’t lay those eggs; in fact they hang from the end of the worm and break off once they mature. These eggs are then excreted into the dung.

Before getting into a horse, tapeworms start with an initial host, which is the oribatid mite (Acari:Oribatida). These mites live in large numbers on pastures and the tapeworm eggs tend to be swallowed whilst the mites are feeding on horse dung. Within two to four months, these eggs hatch within the mites and the horse then swallows the mites whilst grazing. Six to 10 weeks later, the worms mature within the horse.

The most accurate way to see if horses are infected, but very impractical, is via post mortem or during surgery. Three surveys conducted in Kentucky (USA), where the world’s largest horse population live, showed that in 1983, 53% were infected, in 1984 54% were infected and in 1992 64% were infected.

The effects of tapeworms on horses is still not totally understood, but what we do know is that tapeworms are thought to contribute to major colic attacks. Other hypotheses are that these parasites can cause inflammation of the ileocecal valve and they can contribute to ulcers, plus cause the retention of fluids. These problems can cause the horse to have bowel problems. One problem with diagnosing tapeworms is that there are few symptoms that can be easily identified by horse owners.

With tapeworms, the problem is not always to completely cleanse the horse of the parasite, but to make sure that any infestation is limited, thus stopping the horse from having a large burden of these worms. Another problem is that most conventional wormers won’t tackle tapeworms effectively and it may be necessary to use a large dosage of these drugs, which can be comparatively safe when administered by a vet, but not necessarily when administered by the owner. Another method, which in most cases is both inhumane and impractical, is keeping horses off pastures. Whilst this will protect horses from the oribatid mite, it makes little sense to keep horses boxed all day, nor is it good for their temperament. A better solution would be to look at herbal alternatives to wormers, marketed as parasite repellents. Many of these products actually expel the parasites from the horse and at the same time cleanse the gut of eggs and larvae. The larvae are killed or paralysed, thus breaking the life cycle of the tapeworm and solving the problem cost effectively. This methodology of clearing worms and other parasites from horses will be discussed in more depth later.

The History of Worming

The approach to worming has changed over the years and, at the University of Kentucky, Gene Lyons PhD, Sharon Tolliver BS and Hal Drudge DVM documented the history of worming in the scientific journal Veterinary Parasitology. Their paper threw up some unusual practices.

In the 17th century there was a notion that drawing blood from a horse and getting the horse to drink its own blood was a very good way to kill worms and to cure other equine ailments. How a horse was made to drink its own blood was not described. Other historical ways to resolve worms were equally bizarre and included soap, liquorice, linseed oil, chick or human faeces, eggs, guts of chicken or pigeons, and, worst of all, mercury. Owners were advised against using some of these methods with pregnant mares. Feeding horses tobacco was also practised, but the amount needed to have any effect would more than likely make a horse quite ill. Also many people experimented with herbs without proper knowledge of herbal medicine and so rarely getting the required results. However, today’s leading herbal products are very carefully formulated and trialled to ensure the best possible results.

In April 1891 the first edition of the book Veterinary Country Practice was printed. Written by “Qualified and Experienced Members of the Royal College of Veterinary Surgeons”, it was written expressly for Chemists and Druggists. In this book there were several recipes for worming, some containing small quantities of Arsenic, also herbs, including Aloes, Ginger, Liquorice, Valerian and Garlic; also used were Linseed oil, Turpentine, Gentian and this list goes on. There were 11 different recipes, showing that even in the 1890s they knew that it was beneficial to change the treatment to combat resistance. It has to be said it was also to give the less well off a chance to use cheaper ingredients. The last edition was reprinted in November 1935.

Carbon tetrachloride, best known as a component that is used in dry cleaning, was one of the first chemicals used for worming. Whilst it was semi-effective, it was as one can imagine, very toxic to horses.

The 1940s marked the start of a new era of chemical wormers, but even the early chemicals that were introduced, like phenothiazine, were very toxic. Phenothiazine was, however, the first product that would start to attack the strongyles, which until then were a major issue for horses and their owners. But by the 1960s, both in the UK and the USA there was evidence to show that these parasites were starting to become resistant to chemical worming, a situation that was going to make chemical worming a major problem from there on in.

The 1950s saw the introduction of some products that seemed to be effective on a number of different parasites; mixing a number of chemicals together in smaller qualities helped combat the toxicity of a large dose of one product. This cocktail had to be administered by a vet by inserting a tube down the horse’s throat, a manoeuvre which also carried risks. Organophosphates, which were commonly used in sheep dip, were popular in the 1970s. They are very toxic chemicals both to horses and to humans who get in contact with with. Today there are some farmers who used these chemicals in sheep dips, etc., who are suffering from multiple chemical poisoning; in some cases they are totally house bound and cannot live normal lives.

It wasn’t until the 1970s when owners were able to worm their horses themselves without the need to call in the vet to run tubes down a horse’s throat. New products were being marketed as a paste and the first of these was Benzimadazole. This drug had a much larger margin for error and could be administered in much smaller quantities than previous de- worming chemicals. Many drugs from this family of chemicals are still in circulation today. Also in the 1970s Pyrantel was also offered from an alternative family of chemicals. This proved to be very popular when parasites started to get resistant to the benzimadazole products.

In the 1980s Ivermectin was introduced which allegedly kills the larvae of parasites as well as the adults and this product would prove to be very popular with horse owners, especially as it could also be administered as a paste. Finally, in the 1990s we saw the introduction of Moxidectin, marketed on the basis of it being able to kill the pesky small strongyles in the intestines of the horse.

Parasites’ resistance to chemical wormers

Whilst the drug companies would want you to believe that their’s is the answer to exterminating parasites in horses, there is a fundamental problem that exists – resistance. Parasites have had to learn to survive and to adapt to their environments and in doing so they have managed to find ways to adapt to modern chemicals that are meant to stop their reproduction. This is called resistance and these worms are now passing this resistance on to their offspring. There is no single chemical product on the market that stops the resistant parasites and there is evidence to show that the number of resistant parasites is on the increase. Historically it has been believed that rotating the products and using wormers from different chemical families can eliminate most resistant parasites but in a paper published by Blanek, Brady, Nichols, Hutchinson et al. in which extensive studies were conducted in the USA using quarter horses, they concluded that resistance in equine parasites was an ever increasing problem and that more research needed to be done into rotating wormers.

Another problem that blanket rotation needs to consider is the fact that certain classes of drugs are aimed at different families of parasites and unless the horse owner is aware of which parasites their horses carry, they can be using chemicals that can have little or no effect on their horse or horses.

One solution to this problem is to have regular egg counts utilising the dung of the horse. This, however can be costly and very few owners undertake this kind of interest in their horses’ worm problems. The usual thinking is that by carrying out regular worming on their animals that will be sufficient. Another approach that should be considered is using a herbal product as an alternative. There seems little evidence that there are worms that become resistant to the tried and tested herbal products. More details of herbal worming will be discussed later.

Toxic effects of chemical wormers

The one subject that will never have been discussed by the manufacturers of the main brands of wormers is the potential side effects of using chemicals. As has been discussed above, these products are poisonous to worms and unless they are used very carefully, they can equally be poisons for horses. As the resistance to chemicals grows, so stronger dosages need to be used and the safety margins become smaller. The following side effects can be caused by the use of equine wormers: swollen glands, colic, allergies, laminitis, intestinal problems, skin reactions, drooling, hoof problems, internal problems, plus dangers to the horse’s immune system. Let’s face it, horses are not designed to be filled with toxic chemicals!

A good example is toxic hepatitis, which is caused by substances poisonous to the liver. There are three known sources: chemical poisons, plant poisons and metabolic poisons. Chemical poisons include arsenic, copper, mercury and phosphorous among others. It should be noted that tetrachlorethylene and carbon tetrachloride, both used as worming agents, are potential causes of non-infectious, toxic hepatitis, when improperly used.

In addition, there is the environmental impact of these chemicals. Using these wormers mean that these chemicals get into the earth through horses’ urine and faeces. The bigger picture means that other animals, especially wildlife, agricultural animals and pets will be affected. It has been noted that birds that eat horse droppings from chemically treated horses die. These chemicals stay in the land for over three years and can also find their way into streams and rivers, affecting fish, and they can also get into our drinking water. We have a responsibility to our environment not to pollute it unnecessarily.

Herbal Worming

The use of herbal remedies or herbal medicines is thought of today as alternative, but if we examine the evidence, in reality it is the chemical products that should be termed as alternative. Herbal medicine can be traced much further back than any modern chemical treatment. In fact, a large number of medicines used today have their basis in herbal remedies that can be traced from as far as the tribesmen of Africa, the ancient Egyptians and the Chinese.

The first reports of herbal medicine can be dated as far back as 2800BC in ancient China. By 400BC the Greeks had also adopted the use of herbal medicines and by 100BC the first reference book on herbs was written in Greece. By 50AD, herbal medicine had spread to the Roman Empire and by 500AD herbal medicine first came to Britain and was practised throughout Saxon times. By 800AD, herbs were being grown in monasteries in Britain and monks developed the usage of these remedies. At the time of the black death herbal remedies were used to try and contain the spread of the disease. In the 1500s, and during the reign of Henry Tudor, the first laws were passed to control the practise of herbal medicine to stop them being supplied by untrained apothecaries. In the 1600s, medicine in Britain was becoming 2 tier, chemical based drugs for the rich and herbs for the poor. During this period and into the 1700s many conventional drugs were being sold over the counter, but the realisation of the terrible side effects was starting to become a reality. As we move into the modern era, there has been a large resurgence of herbal medicine, partially due to the side effects of chemical products, but also as in many cases natural products are in harmony with nature, so can be more effective.

There are many products on the market claiming to be herbal Parasite repellents that will have little if any effect, so it is always worth investigating what research has been conducted to back up their claims.

There are herbs that are classed as Anthelmintics: these are herbs which have the capacity to destroy intestinal worms and parasites. They come in two categories: vermicides and vermifuges. The former are agents that destroy worms without necessarily causing their expulsion from the bowels and this category of herbs should be combined with laxative or cathartic herbs which then cause the expulsion of the destroyed parasites. Vermifuges are agents, usually having cathartic properties, which expel worms from the bowels.

As well as Anthelmintics there are Taeniafuges and Taeniacides.These are herbs that expel (taeniafuges) or kill (taeniacides) tapeworms in the intestinal tract.

For a product to have a good combination it must include these herbs and also a separate cathartic; this helps not only to loosen the bowels and work as a laxative but to clean the gut walls of the eggs and larvae. Also needed is a good demulcent: demulcent herbs act as a soothing agent to calm any inflamed or damaged tissue, and also to prevent any ‘side effects’ that a strong anthelmintic, especially chemical anthelmintics, can cause. And last, but not least, it would contain a stimulant to prompt the herbs to work as a formulation.

As many anthelmintic herbs are very bitter and cathartics very strong, it is usually a good practice to add a herb that has both a palatable flavour as well as a pleasant aroma; this can be the chosen stimulant or demulcent.

Through in vivotrials conducted at the Institute of Organic Research in Switzerland it has been proven that certain herbs show a significant activity with a 79% reduction in egg output on day five of feeding it and a 100% cessation of egg hatch. The trials also show that the anthelmintic activity either killed or paralysed the larvae so they cannot climb up the grass to be eaten by a new host. This stops the cycle and also prevents the build up of resistance.

It has also been proven in recent trials conducted in the wild, that herbal parasite repellents do not cause any damage to wildlife, the water or the environment.

It is however, essential that before buying a herbal parasite repellent, you check that it has been properly trialled, and that the results prove that it can be used as either a complete wormer or as part of a worming programme.

Environmental Control of Parasites

Controlling parasites on a property can go beyond a good worming programme and the following ideas can certainly help control parasites.

Any new horses arriving, before they are allowed to graze with the other horses, should be isolated for 48 hours and wormed. It is important to know what worming has been done at the property the horse is coming from and if any infestation is known to be a problem there. Even if you are informed that the horse is worm free; do not take that information as gospel and conduct your own worming. Herbal parasite repellents are often good for this situation as you can be confident of not overdosing a horse or giving them a product that might conflict with what they might have been given recently.

During the 48 hour period make sure that all droppings are removed and either have the dung removed from the property or use it as a garden fertiliser so that it is kept away from other horses.

A general consideration is to make sure that paddocks are kept as free from droppings as possible and that will help stop the parasites’ life cycles. Many yards and stud farms use special paddock vacuum cleaners to remove droppings. Again make sure that dropping are disposed of and do not get back in direct contact with horses. Faecal egg counts can also be a very useful tool, and consider the fact that if you have a horse with a large worm burden it is advisable to isolate it from the rest of the herd.


The subject of equine parasites and their control is very complex and a proper understanding of the subject, leading to good worming practice, should maintain clean pastures and healthy horses. It is very easy to fall into the trap of either performing the same worming time in time out or performing a targeted rotation, but these are not necessarily the answers unless the horseman is aware of particular worms that may be affecting their property. The use of herbal parasite repellents should also be considered for good practice as the way that they work, being very different from the chemical approach, breaks the life cycle of equine parasites.


Natural Healthy Horse Care – RH Kerrigan B.Sc, MAIAS, MAAC. (Equine Educational) Parasite Cycle– www.dignosteq.com Should Horses be Wormed– www.soloequestrian.com Equine Internal Parasites – Don Hudson, Dale Grotelelueschen, Duane Rice Natural Horse Wormers – www.successful- natural-horsecare.com Illustrated Veterinary Encyclopaedia for Horsemen (Equine Research Inc.) Bad Bug Basics Karen Biggs DVM, Craig ReinemeyerDVM PhD, Dennis French DVM, MS, DipL, ABVP and Ray Kaplan DVM, PhD (The Horse Magazine) Resistance Worms, do your horses have them? Karen Biggs DVM, Craig ReinemeyerDVM PhD, Dennis French DVM, MS, DipL, ABVP and Ray Kaplan DVM, PhD (The Horse Magazine) Deworming adjuncts – Karen Biggs DVM, Craig ReinemeyerDVM PhD, Dennis French DVM, MS, DipL, ABVP and Ray Kaplan DVM, PhD (The Horse Magazine) Age-related parasites – Karen Biggs DVM, Craig ReinemeyerDVM PhD, Dennis French DVM, MS, DipL, ABVP and Ray Kaplan DVM, PhD (The Horse Magazine) Control for mature horses Karen Biggs DVM, Craig ReinemeyerDVM PhD, Dennis French DVM, MS, DipL, ABVP and Ray Kaplan DVM, PhD (The Horse Magazine) Environment; development and persistence of parasites – Karen Biggs DVM, Craig ReinemeyerDVM PhD, Dennis French DVM, MS, DipL, ABVP and Ray Kaplan DVM, PhD (The Horse Magazine) Bots and beyond- Karen Biggs DVM, Craig ReinemeyerDVM PhD, Dennis French DVM, MS, DipL, ABVP and Ray Kaplan DVM, PhD (The Horse Magazine) Tapeworms, an underrated threat Karen Biggs DVM, Craig ReinemeyerDVM PhD, Dennis French DVM, MS, DipL, ABVP and Ray Kaplan DVM, PhD (The Horse Magazine) Strongyles, the worst of the worms – Karen Biggs DVM, Craig ReinemeyerDVM PhD, Dennis French DVM, MS, DipL, ABVP and Ray Kaplan DVM, PhD (The Horse Magazine) The History of Herbal Medicine – www.herbal-concepts.co.uk Investigation of anthelmintic resistance and deworming regimens in horses – M Blanek, HA Brady, WT Nichols, DP Hutcheson et al. Historical perspective of cyathostomes; prevalence, treatment and control programs ET Lyons, SC Tolliver and JH Drudge. Department of veterinary science Gluck Research Centre, University of Kentucky.

Protein and Performance

The effects of feeding excess dietary protein

The latest research on protein in horses indicates that excess dietary protein, especially processed, can have several damaging effects. These include:

(1) High blood urea and ammonia levels: Protein that is over what is required must be excreted via the urine and the manure. For this to be done it must first be converted to urea and ammonia by the Liver. High blood urea and ammonia levels on a blood test can indicate that the horse is getting too much protein in the diet. However, if horses are getting insufficient dietary energy and are breaking down body tissues for energy, this will also elevate blood urea and ammonia levels.

(2) Liver and Kidney stress: Recent research suggests that over feeding of protein per day exceeds the ability of the liver to convert protein to urea and ammonia for excretion in the urine. This places and added burden on the liver and the kidneys, and high gut urea levels can increase intestinal disturbances, and can be one of the causes of both ‘hanging’ or ‘bursting’ and also loss or decrease in appetite.

(3) Increased fluid and electrolyte demands: To excrete the extra ammonia and urea requires electrolytes and water. This places an added demand on body water and electrolyte reserves and increases urinary output. If, however the horse has a kidney weakness and is unable to handle the excess urea or ammonia there will be a build up of lactic acid with the resulting loss of performance or even ’tying-up’, ‘Azotoria’ and ‘bursting’ or simply fading at the end of a race.

(4) Nervous irritability: High urea and ammonia in the blood affect the nervous system, causing irritable behaviour and restlessness, and can disturb energy production during exercise.

(5) Increased risk of respiratory conditions: High ammonia in the urine contaminates the stable environment. This is especially noticeable in warm weather, the ammonia fumes affect humans and horses alike, irritating the eyes and respiratory system and predisposing to respiratory infections and viruses.

6) Poor performance: Studies in America have demonstrated that feeding excess nitrogen over recommended levels can prolong racing times by up to 3 seconds.

(7) Excess protein can cause calcium deficiency: Feeding excess protein has been found to leach calcium from the body due to increase in Uric Acid causing poor bone density, weak lung walls, weak bowel walls and can lead to internal bleeding i.e. ‘bursting’ and bone fractures.

Research in America has shown that 30% of all the horses bone scanned showed hairline fractures of the lumbar vertebrae over the kidney/loin area. This is due to stress, standing starts, (starting stalls) and partly due to diet, the diet that starts in the paddocks not just in training, Many horses have an inherited kidney weakness and this shows up very clearly in an Iris diagnosis (Iridology) and these horses are more prone to suffering from permanent muscle damage. An inherited kidney weakness can lead to a build up of lactic acid causing Azotoria or ‘tying up’ and pain over the loin area. Myositis which is inflammation of the muscles, in this case the longissimus dorsi (this muscle stretches from the sacrum and ileum to the neck, making it the largest and longest muscle in the body), and psoas muscles, ( the Psoas major flexes the hip joint and rotates the thigh outward, while the Psaos minor flexes the pelvis on the loins and inclines it laterally) the inflammation is caused from stress, i.e. fast starts from standstill, and in some cases it can be secondary to degeneration of bones or joints, Azotoria and ‘tying up’ can also cause inflammation to these back muscles and if not given enough time and treatment can form permanent muscle/kidney damage.

Adult horses (4 years up) only require between 10 and 12% protein, foals and weanlings 14%, 2 and 3year olds 14-16% maximum. Older horses can absorb 12%.

To over supplement is having an extra handicapper!

The horse that is in any form of hard work, i.e. racing, endurance, eventing, has increased requirements for nutrients to perform hard exercise, but over supplementing above their requirements cannot improve performance. A surplus is equally as dangerous as a deficiency, such that a delicate balance is required between feeding enough to ensure best results and overfeeding enough to cause disorders and inhibit performance.

78% of horses fed supplements are likely to receive excess energy, protein and an imbalance of minerals. Excessive levels of individual nutrients occur up to 10 times more frequently when supplements are added, which if incorrectly balanced can still cause deficiencies. Using several supplements can lead to overlap and hence an increased risk of excesses and sub clinical toxicity

For example: an EXCESS of the following can induce:

Iron – selenium, copper, zinc, phosphorous (leading to poorly mineralised bone) and Vitamins E and B12 deficiencies.

Protein – reduced muscle energy levels; prolonged race times; respiratory irritation; body fluid and electrolyte loss.

Iodine – contracted tendons, hair loss, goitre.

Copper – reduced liver function.

Electrolytes – dehydration.

Cobalt – depressed red cell production, fatigue, weakness and loss of appetite.

Selenium – dullness, depression, loss of appetite, weight loss, hoof damage, lameness.

Magnesium – interferes with the levels of sodium and potassium.

Manganese – Nervous problems, muscle tremors and anaemia.

Fluorine – diarrhoea, bone lesions, lameness and general unthrift ness.

Vitamin A – depressed growth, reduced iron, low red cell count, lameness.

Vitamin K – colic, laminitis, kidney damage.

Vitamin D – calcium deposition in blood vessels, heart, lungs, kidneys, weight loss bone and joint damage.

Vitamins and minerals which are all available in herbal form are 100% safe and absorbable simply because having already been digested once by the plant they are easier to absorb by the horse and any excess that are not needed will be easily flushed out by the kidneys or through the bowels.

It has been found after research into horses that ‘burst’ that a much higher percentage, 78% responded to treatment when fed on a majority oat ration, whereas with horses fed on processed concentrates, the response to treatment was much lower approx only 25%.

Equine Iridology Course

Whether you simply want to be able to keep your horse healthy, and understand why he has any issues and what they are, or if you are looking for a rewarding career working with horses, or if you are already a therapist and want to have another ‘diagnostic’ tool, then Equine Iridology could be the answer, it will fit in with any other type of career as once qualified you can work to suit yourself.

However, it has come to my attention that my qualifications both to practice and to teach are being called into question in a certain quarter; not only questioned but also actually denied.

I have been studying, researching and practicing equine iridology and herbal medicines for over 20 years. My clients for both come from the leading players in all equine disciplines, including racing, dressage, eventing and show jumping as well as all round pleasure horse owners. They have stayed with me for years in some cases and the testimonials on this website bear witness to their satisfaction. I have also been consulted by veterinary surgeons on numerous occasions.

I have also taught iridology for 10 years; I was the first to do it in Europe and virtually all practicing iridologists are or were my pupils.

If any potential client or student is therefore doubtful about my credentials they should contact Elizabeth Houghton, H.Ir, MGNI, Dip.Ait, Dip.NNP, BANT Iridology, Personality Iridology, Sclerology, Nutritional Therapy, Food Intolerance Testing, Equine Iridology, at 17 Chapel Lane, Wicken, Cambridgeshire, CB7 5XZ Tel: 01353 723157 Email: ehh@houghtonhealth.co.uk Website: www.houghtonhealth.co.uk, who will be happy to endorse my qualifications and reputation.

I have in fact been invited on three separate occasions to address the International Symposium of the Guild of Naturopathic Iridologists in London, an invitation that is a great honor and is not issued lightly.

My course is a Diploma course, however I must state that contrary to certain claims I have read, there is no Governing or licensing body for Equine Iridology at this time.

The course is a 10 lesson course, and has a test paper for each lesson, the first lesson is an introduction to Iridology and where and how it began, the next lessons cover a different part of the iris, so that it is easier to learn and remember, and finally the last lesson covers herbs and various treatments recommended for the different problems that occur. At the end of the lessons there is a practical exam. You will be required to hand in 5 test cases with your own iridology photos, including brief examination of the horses. After successfully completing the test papers and test cases you will receive the Ellen Collinson Diploma of Equine Iridology. The course is now run by Joey Philips, who qualified with me in 2016.

As this is a diploma/practitioner’s course it is very intensive and it is vital that the knowledge is understood and if there are any queries or problems during the course you are welcome to contact Joey direct. It is also advisable during your learning period to ask horsey friends if they would mind you looking at their horses as you learn each new area, this will give you some practical experience and towards the end of the course you will be asked to do a few case histories.

I feel confident that this course will give you a concise and detailed knowledge of Equine Iridology, once qualified I am happy to give advice if needed, and you will be put on the register of Equine Iridologists.

The course is available online. For more info please email: info@equineiridologycourse.com

©2024 Ellen Collinson