Pasture and feed  
  1. Overview
  2. Signs of myco-toxicity/mineral imbalances
  3. Myco-toxins
  4. Toxin-binders explained
  5. Grass tetany in horses
  6. Mineral imbalances: especially sodium, potassium, magnesium and calcium
  7. Respiratory problems
  8. Nose bleeding
  9. Skin conditions
  10. High sugar and lack of fibre
  11. Fibre requirements relative to lifestyle
  12. Why add fibre?
  13. How much fibre?
  14. B-vit deficiency is caused by a lack of fibre
  15. Selenium
  16. Photosensitivity - the real cause of sunburn and mud fever
  17. Head flicking/shaking
  18. Head flicking case studies



How pasture and feed can affect your horse


Until recently I had no idea of the impact that various aspects of pasture can have on the health and temperament of our horses. Go through the list of symptoms carefully. As you read, light bulbs will go on for you regarding horses you currently own or know of, or have owned or known in the past. You too will realise how countless, perfectly good horses have suffered, been punished, become 'problem horses', caused accidents, labelled 'bad', 'nuts', 'unmanageable', deemed unrideable, diagnosed with brain tumours, wobbler syndrome, fractured pelvis and sent to the knackers, all because of the grass!!!


This information provides an explanation for many things going on with our horses where extensive investigations have previously failed. It comes from years of my own personal observations and experiences and those of the hundreds of horses and riders I have met and assisted over the last ten years throughout New Zealand and Australia. Additionally, in the spring of 2004, I conducted the Equine Health and Behaviour Survey in New Zealand, the results of which have been very revealing.


Please take part in the Gotcha Equine online survey so we may identify any other issues that may be specific to Australia. Findings and any new evidence will be posted on the Gotcha Equine website, so it's a good idea to visit Gotcha Equine regularly.


Scientists, investigative vets and universities around the world are releasing information and findings on a lot of the areas we are working on. After field testing and further investigations we will then be able to pass this information on to you. It is important to understand that science and therefore the literature is always five to ten years behind the anecdotal evidence which we have a considerable amount of.


Horse owners frequently experience unexplained changes in their horse's temperament and personality. If you are like me and believe that horses do not 'plot against us' and are definitely NOT 'dirty', 'nutty', 'mongrels', 'bitches', 'pigs', 'bloody cows', 'have got attitude' (the list goes on!), then there must be other reasons for this kind of behaviour. There is a strong correlation between soils and pasture and the raft of health and behavioural problems our horses are plagued with. Some mildly, some chronically and sometimes acutely. Aggressiveness, herd bound behaviour, pasture heaves, obesity and laminitis are just a few that spring to mind.


For example, things have been going great with your horse and then he starts spooking at things in the arena, or rushing out of the float, or you are paying for a lesson and he's not 'himself', so it's a complete waste of money. All of these sorts of things:


  • He doesn't like being touched or brushed.
  • I've had the saddle fit checked but it's still like he's got a sore back.
  • Why do some horses bleed from the nose when they're out at pasture?
  • What is the cause of head-shaking/flicking?
  • Why can't I get rid of that mud fever?
  • How come my horse has got sore feet?
  • How come my horse goes to bite me when I'm doing up the girth?
  • I'm feeding my horse heaps but he won't put on any condition.
  • My horse is on 'nothing' but I can't keep the weight off.
  • What is the cause of many respiratory troubles?
  • What is the cause of many skin troubles?


I believe the answers to these questions and many, many more, lie within the following information.


NB. The following information is not intended to replace veterinary advice, merely to give you an overview. If symptoms persist or are acute, please contact your veterinarian.


We are very interested in any feedback and experiences you may have had. Please email Gotcha Equine . Please include your phone number in email correspondence.


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Aspects of Pasture Overview


Horses are either kept on pasture primarily meant for other stock like sheep or cattle, or on paddocks grazed by horses alone. Both situations lead to problems. The former consists of high production grasses (e.g. Rye/Clover mixes) which, because of our climate and the fertiliser regimes applied to them, reach even higher production. This is counter-productive to the health of the horse, whose digestive system is highly specialised and different to other species. Their natural diet of grass, herbs, shrubs and leaves is RICH in fibre and POOR in carbohydrates.


High production grasses are LOW in fibre and HIGH in sugars and carbohydrates and are very prone to serious mineral imbalances. They can be VERY high in potassium and nitrates and low in sodium. This in turn causes the horses system to be 'stripped' of calcium and magnesium. Add to this that some grasses have oxalates which predominately bind up calcium but will also bind magnesium. Some departments of primary industries in Australia recommend not to graze horses on 100% oxalate pastures for any more than four to six weeks at any one period of time.


A large majority of pastures are under half the recommended calcium levels and a large part of Australia also has low zinc levels. Combined with oxalated grasses this is a bad combination for horses and they must be properly supplemented to help avoid a major mineral imbalance such as 'big head disease' (Nutritional Secondary Hyperparathyroidism (NSH)) and magnesium deficiencies.


Nutrient uptake by grasses is influenced by many things; soil pH, type of soil, water content, air and soil temperature, fertilisers, organic matter and stress (such as livestock grazing). As these elements vary so will the nutritional uptake. Also, some pastures and plants accumulate specific elements. For example, Lucerne (Medicago sativa) accumulates calcium; Annual Rye Grass accumulates nitrates; Salt Bush accumulates selenium.


Fertilising with superphosphate, urea or nitrates, accelerates growth and causes plants to be shallow rooted and therefore less able to uptake minerals from deeper in the soil. Urea will also create more non-structural carbohydrates (NSC) in grasses. These also lower the pH (acidifies) the soil and pasture, which then reduces the availability of all major minerals. In healthy soil there needs to be the right balance of fungi to bacteria. The lower the pH, the more fungi and the less bacteria. Fungi really thrive in these acid conditions. Rye Grass also loves a lower pH. This IS the root cause of why MYCO-TOXINS and MINERAL IMBALANCES are such a big problem.


Add to this the fact that the paddock of green, growing grass your horse is grazing is the equivalent of a bowl of sugar! Then we go to the feed store and buy more sugar in the form of molassed grains. No animal stays healthy for long when their diet is predominantly sugar. This high sugar/carbohydrate, low fibre intake leads to, amongst other things (see obesity) an impaired insulin response also known as a metabolic imbalance. This contributes to insulin resistant and 'diabetic' horses and ponies which are prone to laminitis and eventually the Cushing's-like syndrome. It also leads to restricted peripheral circulation (e.g. in the hooves) and hind-gut acidosis, which has much more serious consequences than the horse just having runny manure for a few days!!!


Many horses graze pasture that is termed 'horse-sick' because it is never fertilised or attended to. It will likely have a low pH (docks, thistles, blackberries and other undesirables love this environment) which, as already mentioned, also suits the endophyte Rye Grass and fungal populations in general and also tells you loud and clear that the soils lack, amongst other things, calcium and possibly magnesium. A soil test will confirm this.


Add all this to the fact that Perennial Rye Grass (Lolium perenne), Paspalum (Paspalum mandiocanum) and Couch (Cynodon dactylon), containing endophyte fungi that produce myco-toxins and Kikuyu (Pennisetum clandestinum), under certain conditions contain toxins that are all known to affect the health of stock, can quite often be the dominant grass species. Something else to keep in mind is horses grazing on Couch Grass or White Clover; under certain conditions these grasses can produce cyanide otherwise known as prussic acid poisoning. Affected horses have been know to become very dangerous and can have 'bucking fits' and become uncontrollable, placing the rider or handler in very real danger.


Myco-toxins are present in varying degrees, on and around ALL plants everywhere, including legumes.


Some strains of Rye Grass can be more virulent than others. Stress on grass caused by drought, or being eaten by an insect or an animal, causes myco-toxin production to go even higher.


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What are the Signs of Toxicity and/or Mineral Imbalances?


Because the signs of toxicity and/or mineral imbalances tend to happen unpredictably and simultaneously, especially coinciding with flushes of pasture growth, it can be difficult and fruitless to try and differentiate, so it is best to address both issues regardless. Some myco-toxins have also been found to bind up nutrients such as magnesium.


  • Toxins are ones that have been ingested with pasture or feed. They generally respond to a toxin-binder or removal from pasture.
  • Mineral imbalances are complex and it is important to consider the inter-relationship of them all. Excess of potassium and deficiency of the macro-minerals such as calcium, magnesium and sodium has very serious consequences. They require urgent attention in the short term in the form of appropriate supplementation. Horses kept on a dry lot or stabled will also require vitamin and mineral supplementation.


Meanwhile, if your horse exhibits any of the following, it is highly likely he is 'affected' by his diet, in particular the grass he is eating.


Often starts with:


  • General 'tetchiness',
  • An unwillingness to be touched or tensing up and reacting when touched, especially around chest and thorax,
  • Appears somewhat 'stiff', stepping short behind.


This can cause:


  • Cinchiness/girthiness, not standing for saddling/mounting,
  • General crabbiness when ridden (e.g. pinning ears, swishing tail, etc),
  • Tightness, tenseness, impulsiveness, wanting to run off,
  • Can't use your legs,
  • Reaching around to bite the girth when ridden.


Progresses to:


  • Touchy around ears, difficulty with bridling,
  • Flings off suddenly when haltering,
  • Sore across the loins,
  • Uncharacteristic bucking when first moves off with girth tightened,
  • Excessive aggressiveness towards you or other horses (e.g. viciously biting you, attacking, hounding other horses, you think they're a 'rig'),
  • Excessive herd bound behaviour (e.g. screaming maniac, irrationally attached to another horse). Can exhibit both these previous two 'opposite' behaviours concurrently!,
  • Bucking (quite violent and 'out of the blue'),
  • Bolting off in short bursts,
  • 'Nutty' or 'ballistic' behaviour.




  • Excessive spookiness/alertness,
  • Shies away when approached, hard to catch,
  • 'Spaced out', 'wired', 'not there', hallucinating,
  • Eyesight seems to be affected, can't judge jumps,
  • Overly claustrophobic, extremely sensitive to noise (reluctant to ride close to the arena wall, rushes off the float, etc).




  • Heavy on the forehand, stumbling over nothing,
  • Standing 'base-wide',
  • Difficulty backing up, out of floats, etc,
  • Discomfort walking downhill,
  • Slightly drunk or 'zonked' looking,
  • Uncoordinated movement, staggering,
  • Giving out in the hind-quarters, laying down a lot in the paddock,
  • Dragging back feet, reluctant to go forward,
  • Reluctant to canter, won't canter.


Heat stress:


  • Instantly overheats when you put rugs on,
  • Running madly around paddock for no reason (while other horses aren't),
  • Slamming into fences/gates,
  • Excessive sweating, white sweats, smelly sweats,
  • Sweating in unusual places (e.g. on top of rump, patches on upper neck),
  • General agitation,
  • Fence walking.




  • Like a bug has flown up their nose, can be worse on sunny days,
  • Head twitch.




  • Jerky upward action of the hind limbs.




  • When autopsy shows hind gut necrosis due to vaso-constriction of blood supply to the intestine.




  • Raging seasons, not cycling properly,
  • Difficulty getting in foal,
  • Abortion,
  • Prolonged gestation,
  • Reduced milk production,
  • Weak suckling by foal.




  • Chronic dull/rough coat,
  • Won't put on weight, looks wormy but not, no top line,
  • Bloated or 'potty' belly, looks fat but neck and rump are normal or thin,
  • Consistently small, frequent manure,
  • Scours/diarrhoea,
  • Lifeless eyes, dull, nobody home-glazed eyes,
  • No energy, lethargic,
  • Falling asleep on their feet (like narcolepsy).


Please read what's wrong for a quick and easy way to find out what could be your horse's problems.


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Perennial Rye GrassMyco is the Greek term for fungus. Toxins mean poison and are produced in various types of fungi. Some of these fungi live inside the plant and are called endophytes. Perennial Rye Grass (pictured left), which is the predominant grass in New Zealand and is also found in Australia and many other parts of the world, contains endophytes which produce two very harmful myco-toxins, namely Lolitrem B and Ergovaline. Annual Rye Grass, where as it doesn't contain the dangerous endophytes can have a highly poisonous bacteria form on the seed heads. A toxic bacterial gall is formed and some may exude a yellow slime. Both the endophyte and bacterial gall will still be present in hay even if it has been stored for years. Annual Rye Grass is also a nitrate accumulator.


Paspalum Seed HeadPaspalum (pictured below and right) in New Zealand and Australia can become a dominant grass in horse sick paddocks, particularly during summer and autumn when most other grasses will have browned off.


Paspalum contains high myco-toxin levels in the plant close to the ground and also has a highly toxic ergot that can form on the seed head. Both Rye Grass and Paspalum are known to cause the staggers, otherwise known as the Rye Grass staggers or Paspalum staggers.


Make it your business to be able to recognise these grasses. When not in seed, Rye Grass is characterised by a narrow, dark green leaf that is shiny on the back. Some species of Paspalum have a purple tinge around the edge of the broad leaves.


The Rye-Clover pastures seen on most New Zealand farms is nothing short of disastrous for horses and will cause you nothing but trouble! View our current list of dangerous grasses for horses in Australia.




Clover is one third higher in sugar and starch than grass. All Rye Grasses are high sugar grasses, therefore, even when they have had the endophytes removed, as in low or zero-endophyte strains, they are still not suitable for horses. Horses thrive on the high fibre diet (pictured below left). Have you ever noticed when the grass browns off in the late summer that horses 'bloom' and are 'easier going'? It is the same in winter when they are eating more hay and the grass is not growing at all or very slowly.


A horse in blooming health with excellent feet. He was just rounded up off the country in the adjoining picture.




Equally dangerous are the myco-toxins produced by fungi that live on the outside of plants and in the surrounding soil, especially on the seed heads and in any decaying matter. You will perhaps have heard of the ergot, rust molds and facial ecsma spores. Maybe even of Aspergillus, a known asthma allergen in humans.


Until recently, we horse owners didn't take too much notice of fungi in our horses' environment, apart from knowing not to feed mouldy hay or feed. Because they are usually invisible and myco-toxins do not show up in blood tests, it has taken a while to make the connection between many health and behaviour problems in our horses and these insidious equine trouble makers! Some horse owners suspected a form of poisoning was occurring, having their soils tested for heavy metals and putting water filters on their troughs.


In 1985, the World Health Organization estimated that approximately 25% of the world's grains were contaminated by myco-toxins. This figure has most certainly grown since then due to an increase in global import and export of grains and cereals and the changing environmental and weather patterns.


Our climate, and the generally low pH of the soils, means the conditions are frequently very favourable to the explosive proliferation of fungal spores and myco-toxins. Particularly in tropical areas where moist, warm conditions are paramount. If you happen to live anywhere near any orchards you will know how often they spray for fungi. You will have seen mould suddenly appear on horse manure from time to time or when the mushrooms appear in late autumn and early winter. Fungi love acidic conditions, so pasture fertilised with traditional superphosphate makes an ideal environment for them.


The lifestyle of the typical horse means they spend most of the time out grazing the pasture. Consequently, they are inevitably ingesting and inhaling vast numbers of fungal spores and myco-toxins 24/7. Not just at certain times of the year, but any time the conditions favour fungi!


Myco-toxins have also been directly linked to the extended gestation period for mares in foal as well as dystocia (difficulty birthing), lack of milk production, premature separation of the placenta and other placental irregularities. Weak or dead foals that may have suffered trauma or asphyxiation due to difficult birth or the foal may be weakened because of placental insufficiency.


It is no surprise that the results of the Equine Health and Behaviour Survey in New Zealand fit with this information. The horses with the most and severest symptoms are invariably grazing the 'improved' pastures, especially the Rye/Clover mixes. Of these, most are also being fertilised with superphosphate. However, there are some horses with severe symptoms that live on Rye Grass pasture that hasn't been fertilised in ten years and some that graze 'low-endophyte' pasture and still show symptoms. Thousands of horses suffer for many months of the year, from an array of the symptoms.


To help us identify as many bad grasses and symptoms to further help other horse in Australia, please take a few minutes to fill out our online survey.


All of the 'severe' cases have exasperated owners who have spent many hundreds, sometimes thousands of dollars investigating other possible causes. They have had numerous blood tests (which time after time come up clean or show just mild anaemia), equine practitioners of all descriptions, multiple saddle fittings and sometimes up to three new saddles, horse dentists and hoof trimmers. Finally, they hear about feeding the right vitamins and minerals and a toxin-binder. Toxin-binders are a completely natural food that locks onto toxins in the horses' intestine, prevents them from going through the intestine wall and into the bloodstream, and carries them out with the manure. Within days owners are astounded at the difference in their horses. Even their husbands notice improvements!


Due to the fact that there are hundreds of different myco-toxins lurking in and around all pasture types it is no surprise that the above scenario is very common. Feeding a toxin-binder is simple, comparatively inexpensive and totally safe. If your horse has any of the symptoms mentioned under signs of toxicity and mineral imbalances, it would seem logical to go down this avenue along with addressing mineral imbalances.


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Toxin-Binders Explained


A toxin-binder helps to protect the horse from the toxins which can cause ill-health. It is NOT a cure. The yeast cell wall extract provides lots of 'sites' for toxins in the feed to latch onto and takes them out with the manure. Sometimes, when the climate favours proliferation of fungi, or grazing very short grass close to the roots, or when seed heads are present, the toxin-binder has its work cut out. When these conditions exist you will need to up the dose, feed morning and night or completely remove the horse from the pasture until the horse 'cleans out' and comes back to normal. Horses do not become 'immune' to the toxin-binder; how could they as it does not enter their bloodstream.


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Grass Tetany and Horses


I now believe various degrees of grass tetany is the fundamental root cause of most of the health and behavioural issues with our horses. Because the symptoms are so wide and varied it has taken a long time to put two and two together. Read More Mysteries Solved to learn how excess dietary potassium affects your horse while the following paragraphs explain how potassium-nitrate can become a major problem.


For those who get bamboozled by science, in very simple language, the cool, cloudy, wet weather of spring and autumn (including frosts and freezes) cause acute spikes of potassium and nitrate in the grasses our horses are eating. This grass may only be 1cm long, but under these climatic conditions it can have a drastic effect on your horse. This effect can be made worse by high protein feeds, as protein converts to nitrate which has to be somehow eliminated at the expense of your horses calcium and magnesium supply. Fertilised Rye Grass and Clover are the worst for this scenario but ANY grasses under the 'right' conditions can have the same effect. This is why it is so important to have somewhere you can keep your horse completely OFF the grass during these times (early spring, autumn to early winter and drought breaking rains).


All the literature I have read says that horses don't suffer from nitrate toxicity like other stock. Indeed I have a copy of a letter from a prominent Canterbury vet who says that there is no evidence that horses suffer from grass tetany at all! He couldn't be further wrong!


As the following paragraphs explain, it is not the nitrate directly but the fact that it enters the system as potassium nitrate. The excess potassium and toxic nitrate is excreted by latching onto calcium and magnesium indirectly, causing a serious deficiency of these vital minerals and all the associated health and behaviour issues (an extensive list!).


For those who need a more scientific explanation, whilst the article refers mainly to cattle, Dr. Swerczek has since done trials on horses which prove they are affected by the same process. Grass, even if it is very short, can be dangerous under certain conditions which include a drought breaking rain. Read Dr. Swerczek's brilliant article, Don't Short Salt.


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Nitrate Toxicity, Sodium Deficiency and the Grass Tetany Syndrome


Excerpts from "Nitrate Toxicity, Sodium Deficiency and the Grass Tetany Syndrome" by Dr. Swerczek, DVM, Ph.D.


Numerous researchers have found that grass tetany occurs most often in older brood cows grazing lush growth of pastures in early spring. The triggering of the grass tetany syndrome includes environmental conditions of cool, cloudy and wet weather, promoting rapid, lush growth of cool season grasses. These environmental conditions, which also include frosts and freezes, will cause acute spikes in potassium as well as nitrate in affected growing pastures. Analysis of these affected pastures during and after periods of frosts and freezes revealed elevated levels of potassium and nitrate.


Nitrate in the form of potassium nitrate is reportedly the form which herbivores are exposed to nitrate. During periods of stress to pastures forages, the acute spike in potassium and nitrate is seemingly causing an electrolyte and mineral imbalance in affected herbivores.


If nitrate is excessive, a hypomagnesia (magnesium deficiency) and/or hypocalcaemia (calcium deficiency) may develop as the body is eliminating magnesium and calcium with the excessive anionic nitrate. However, if there is adequate sodium in the diet, organs and tissues, the excessive anionic nitrate is removed by the gut, kidneys and mammary glands in lactating animals, as a ionic complex associated with sodium, magnesium and calcium are maintained at physiologic levels and hypomagnesia and/or hypocalcaemia will not occur.


For this reason adequate levels of sodium in the body and ration will lessen or prevent the drastic effects of nitrate toxicity. Also, it explains why adequate sodium in the diet will aid in the prevention of grass tetany, which is associated with high potassium and low magnesium levels.


It is apparent that nitrate toxicity in herbivores is much more prevalent than previously reported. A well documented form of nitrate toxicity occurs in ruminants when nitrate is converted to nitrite by the microflora of the gastrointestinal tract and then the nitrite induces a methemoglobinemia and anoxia. However, it is hypothesised that a much more common mode of nitrate toxicity, and previously not recognised, is when nitrate toxicity induces a severe electrolyte and mineral imbalance in ruminant and non-ruminant herbivores. This form of nitrate toxicity is an important factor in the pathogenesis of the grass tetany syndrome and likely other syndromes in herbivores, including reproductive disorders in all herbivores, including horses. Seemingly, adequate dietary sodium not only protects against nitrate toxicity, but also aids in the prevention of the grass tetany syndrome in herbivores and other metabolic and reproductive disorders induced by nitrate in herbivores.


The high nitrate in the milk may also explain why neonates seemingly are affected with a multitude of opportunistic gastrointestinal diseases, including gastric ulcers and other intestinal disorders. Conversely, dams fed a low protein diet and adequate sodium rarely have neonates suffering from these gastrointestinal disorders.


Potassium promotes the overgrowth of saprotrophic (micro-organisms that normally grow on dead matter), commensal (organisms that live together but don't harm each other) and pathogenic (microbes that cause disease) micro-organisms in plants, especially plants damaged by droughts, frosts and freezes. Thus, such forages become the source of many opportunistic, potentially pathogenic bacteria and fungi.


After ingesting them, livestock face an overgrowth of opportunistic, pathogenic organisms in the gut. The organisms rapidly proliferate to produce toxic by-products, like excessive ammonia, which is acutely toxic to foetuses and the immune system.


These pathogens infect not only the foraging animals but their foetuses. Early and mid-term foetuses may abort, while near-term foetuses may suffer premature birth, and/or septic weak neonatal birth. Similarly, it's felt that high-potassium forages encourage excessive growth of endophytic and other pathogenic fungi, especially in Fescue and Rye Grasses. The toxins these fungi produce add to the reproductive problems in cattle and horses.


View video of grass tetany.


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Mineral Imbalances

Especially sodium, potassium, magnesium and calcium deficiency.


Unless you have been organically farming for years, your pasture WILL BE minerally imbalanced. In particular it will be deficient in calcium and possibly magnesium. Rye Grass and Clover are inherently very high in potassium and low in sodium, especially under certain climatic conditions frequently encountered in autumn and spring. These macro-minerals are so vital to life that if the animal isn't getting them from the grass he is eating then we must supply them in the form of a supplement for the following very good reason.


The body pH of the horse (or any mammal including us) is supposed to be 7.365 (slightly alkaline). When the pH drops to less than 7, from eating too much sugar/carbohydrate from grass and molassed grains, the body becomes acidic. Numerous health problems arise from this state of 'acidosis'. If the diet does not contain enough calcium and magnesium then the body has to continually swipe these vital minerals from the bones, muscles (including the heart), nerves and brain, to maintain this ever so slightly alkaline pH.


In layman's terms, here are some facts. Think about them and draw your own conclusions! Calcium excites the nerves and magnesium relaxes them. The brain is part of the nervous system! Attention Deficit Disorder type symptoms - they 'lose the ability to process information' (can't think straight), you have difficulty getting their attention, they become over-sensitive, spooky and cause accidents and so on. Calcium is necessary for muscle contraction and magnesium is necessary to release them. Horses are 80% muscle; lack of calcium/magnesium causes 'spasticity' of back muscles, tight hamstrings, tenseness, muscle cramps.


Boron is a 'synergist' for calcium and magnesium, which means it helps calcium and magnesium to do their jobs. In the absence of boron, up to 40% of calcium and magnesium is lost in the urine. Boron is also commonly lacking in our soils, more so in regions of high rainfall. Calcium, magnesium, boron along with copper, are high on the list of minerals necessary for proper bone formation and maintenance as well as joint health. Spring time (worst time of the year for mineral imbalances) is when mares are in the third trimester of pregnancy and are nurturing their growing newborn foals (increased requirements). Lime is calcium, so liming is a good start and will help take care of part of the daily calcium requirement. Magnesium is not so easily applied via the soil short term.


Our climate in New Zealand and Australia is changeable, warm and wet. The spring and Autumn 'flushes' are well known with their associated problems, but there are many slightly lesser 'flushes' throughout the year depending on climatic conditions. Rapidly growing (short) grass which is usually bright lime green, even the tiniest shoots will be full of potassium and NSC, this mainly occurs in autumn and spring. Excess NSC can trigger laminitic attacks, especially in horses that are prone to laminitis. The surge in potassium will cause a major mineral imbalance; until just recently this has not been recognised at all in horses. It has been well documented in cattle and is called grass tetany or known as 'grass staggers', to differentiate it from 'Rye Grass staggers' caused by the Lolitrem B endophyte in the Rye Grass.


Horses with grass tetany will show symptoms very quickly, usually overnight. They will suddenly appear very stiff in their hind legs and may even look like they are lame in the back leg(s). Some will even point their back toe like they have a hoof abscess and if left then the next morning you could find them pointing the opposite back leg. Some horses will have trouble getting up from laying down, and some can't get up. If not treated it could lead to long term effects on the horses movement and in severe cases it can be fatal. Some horses will show mild signs by stepping short with their back legs.


Any grass under stress or climatic conditions such as those of early spring and autumn, especially in drought-breaking rains or cool, cloudy, wet weather, including frosts, is subject to acute spikes of potassium and nitrate at the same time becoming low in sodium. This is exacerbated by nitrogenous fertilisers. The potassium nitrate ingested is highly toxic and the body eliminates it by latching onto calcium and magnesium and is excreted with them. Hence the necessity to feed adequate calcium/magnesium and sodium while not adding to the potassium load with Lucerne/molasses, many herbs/garlic, high protein feeds and supplements containing potassium.


There is a huge emphasis on grass production and comparatively little on the health of the stock that are eating it. Many of the pastures our horses are grazing are primarily for sheep and cattle and are more suitable for improving weight gain and milk production. Furthermore, they are fertilised with substances that promote rapid growth, thereby exacerbating the mineral imbalances. In Australia it's not uncommon for large cattle farms to be subdivided up into smaller lifestyle properties which are subsequently used to graze horses.


Magnesium is one of the most important minerals in the cell. Some magnesium is stored in the body, mainly in the skeleton, along with muscles including the smooth muscle of the heart from where it is released when deficiencies occur in the diet. Magnesium plays a vital role in the activation of around 350 enzymatic processes in the body including breakdown of blood glucose. Blood magnesium levels rise after the horse eats glucose or carbohydrates. Simplified: low magnesium = a reduced insulin response. It therefore contributes significantly to the development of obesity, the 'diabetic' horse, associated laminitis and eventually to the "Cushings-like" syndrome.


Spring grass is especially high in glucose and low in minerals including magnesium. Deficiencies affect the cell membranes of nerve and muscle tissue, leading to many of the above symptoms, especially the 'hypersensitivity' ones. Magnesium is one of the essential electrolytes, along with calcium and potassium. Too much calcium and/or not enough magnesium can predispose a horse to 'tying up' (severe muscle cramps).


Symptoms include:


  • Excessive spookiness/alertness/excitability,
  • Stepping short behind, not tracking up,
  • Chronic saddle fitting problems,
  • Loss of appetite/poor condition,
  • Nervousness,
  • Exhaustion,
  • Cramps,
  • Cardiovascular irregularities,
  • Hypersensitivity to noise,
  • Grinding the teeth, doesn't like the bit, unquiet mouth.


Epsom salts (magnesium sulfate) can be fed short term, however, regular feeding can lead to gastro-intestinal upsets, even diarrhoea. Magnesium oxide is a form of magnesium that is usually applied to the soil. From there it would be processed through the plant into a form that the body can utilise. It is imperative to feed a highly absorbable, organic form that is non-toxic and whatever the horse doesn't need will go out with the urine or manure. Magnesium needs to be part of the right feeding regime for your horse, according to his lifestyle.


Kikuyu grass contains oxalates which bind up calcium making it unabsorbable by the horse's intestine (read bad grasses for other oxalate grasses in Australia). Horses grazing pastures with significant proportions of Kikuyu definitely need to be supplemented with calcium. Feeding some Lucerne along with a good calcium supplement is a good option, but bear in mind some horses can not tolerate Lucerne because it is high in potassium and fluorescing pigments which can cause photosensitivity. Photosensitivity can appear as a persistent mud fever or sun burn particularly on unpigmented skin of white patches (see photosensitivity). Kikuyu grass is not high in nutrition and it is important to have a good feeding regime when Kikuyu is prevalent in your pasture.


Calcium is very important particularly when the majority of soils in Australia are generally under half the calcium levels recommended. Calcium is crucial for good gut health in horses, not to mention for all their vital organs. Leg splints can form for no apparent reason and facial crests can form on growing horses that are not getting enough calcium while grazing Kikuyu. In Queensland and Northern New South Wales, oxalate grasses are a huge problem. There are some warnings about the grass but depending which state or territory you are in the information may be contradictory to an adjoining state and very confusing.


In Queensland and Northern New South Wales, it is commonly known as big head disease or bran disease (Nutritional Secondary Hyperparathyroidism (NSH)). Common symptoms of 'Big Head' are affected gait, poor performance and swelling of bones of the head. Horses grazing oxalate grasses, like Setaria or Kikuyu for a period of time that are not being properly supplemented in calcium, may experience demineralisation and possibly an enlarged thyroid gland or otherwise known as goiter. The parathyroid gland inside the thyroid releases a hormone which melts the bone to maintain calcium levels in the blood. If calcium levels drop in the blood below normal this could have a detrimental effect on the horse's survival, so their body is designed to maintain the correct calcium levels at all times (this is called homeostasis). That's why it's unusual to see low calcium levels in blood tests. If you do see this, the horse would be by this time seriously ill.


Kikuyu grass also binds up sodium so it's important to also feed plain (non iodised) salt. Salt can also act as a buffing agent for acid in the horse's body, including lactic acid and acidosis of the hind gut. Salt is also vital for the drinking reflux. Over autumn and winter, if you notice your horse's manure getting dry this is probably because they are not drinking enough water in the cooler conditions. Increase the salt by 10gms each couple of days until the manure is back to normal. A good starting guide for feeding salt is 10gms per 100kg of body weight.


Salt and calcium are the two things that will vary in horses diets according to the situation they are in. For example, heavy work load, extra sweating or in foal. Vitamin and mineral supplements on the market are designed to add calcium and sodium separately for this reason, the only problem with this is they DON'T TELL YOU! Fine, non iodised salt is easily available at your local produce store.


It is important to note that for proper calcium absorption, other elements such as magnesium, boron and copper must be present. It has also recently been documented that magnesium is also bound up by oxalates, although not to the same extent as calcium, but it explains why so many horses on oxalate pastures are also showing all the signs of magnesium deficiencies.


Horse people are notorious for thinking that if one scoop is good two must be better. This is not the case with vitamins and minerals. There are some minerals such as selenium that can become toxic if overdosed. Calcium and salt should also not be overdosed, so always stick to the manufacturer's dose rate or check with your veterinarian.


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Respiratory Problems


Respiratory problems may be caused by inhaling toxins and pollens which are allergens or "Hyperkalemia" (too much potassium) or high nitrate levels. These symptoms therefore don't respond to a toxin-binder.


Symptoms include:


  • Inflamed nasal membranes,
  • 'Runny' noses, gunk in the corners of their eyes,
  • Blisters/ulcers up the nose (swabbing proves negative for Herpes),
  • Coughing in paddock and/or on exercise*,
  • Excessive snorting,
  • Breathlessness, laboured breathing, out of 'puff' after very little exertion, can't get fit**,
  • Wheezing,
  • 'Gunk' out of one or both nostrils periodically,
  • Nose-bleeding when at rest out in the pasture.


* Coughing during exercise and an enlarged goiter/thyroid gland can be a symptom of too much iodine. Another reason not to feed too much iodine such as iodised salt or spirulina).

** Also a major symptom of 'Hyperkalemia' (too much potassium or high nitrate levels).


Many horses that suffer from one or more of the above symptoms, some to the point where they are retired or their careers cut short. Once again, extensive investigations which involve scoping, blood tests, etc. are often fruitless and expensive. On a sunny day, hold your horse's nostril open towards the sun and look up the nasal passages. Hopefully it is pink and clean looking. If it looks inflamed, or looks yellowy and bumpy, or there are little 'blisters' or even larger ulcerations, then your horse could have one of the allergies we are talking about.


When you think about it horses have their noses down in the grass eating most of the time. Whilst they are eating they are also breathing. There are squizzillions of fungal spores in the grass which get sucked up their noses. For instance, spores from the rust moulds and aspergillus fungi, both very common on our pastures, are known to cause hay-fever and asthma in humans. It stands to reason that some horses will also have allergic reactions to them. In fact some of the symptoms in our horses are very similar to asthma in humans.


If your horse has laboured or noisy breathing (symptoms similar to asthma), then he is suffering from constriction of the airways. Remember that magnesium is a natural dilator so keeping magnesium levels right up there is hugely beneficial. Addressing mineral imbalances is vital - you need to get the potassium DOWN and the sodium, calcium and magnesium UP.


Lush, moist pasture can be high in potassium and is the ideal environment for fungi so is best avoided for horses with respiratory conditions. It goes without saying to feed good quality, non-dusty (dunk in water if necessary), non mouldy hay. Leaving matter to decay on the ground, such as toppings, also creates a wonderful environment for fungi.


An interesting fact is that when your soil is biologically active and minerally balanced (pH up towards 7) fungi will not thrive, whereas they love an acidic environment. By attending to the 'cation capacity' (calcium, magnesium, sodium and potassium balances) the pH of the soil will improve. This reduces the fungal populations to the optimal level.


One suggestion in the meantime, is to smear some Vaseline around the inside of the nostril to catch the spores and pollens on the way up. Apparently you can do the same thing on aeroplanes and buses to prevent other peoples' germs going up your own nose!


Keep magnesium intake right up there as when magnesium levels decline, the incidence of allergies and asthma rises. Also see mineral imbalances.


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Nose Bleeding


This can occur when the Aspergillus fungus 'sets up camp' in the walls of the guttural pouch of the poor horse. Their preferred location is on one of the major blood vessels that are right there. The blood vessel gets damaged and bleeds. It's as simple as that. Sometimes this colony of fungi damage nerves in there, which can cause difficulty swallowing.


Unfortunately it's not that simple to eradicate. It's a serious and debilitating condition and horses have been known to bleed to death. Surgery may be required. This form of nose-bleeding is not related to exercise. If it is induced by exercise there is a different cause.


Read Dr. Dwayne Bennett's article, The Whys and Wherefores of Gutteral Pouch Disease.


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Skin Conditions


I am talking about the persistent ones that don't respond to normal treatment regimes. Where the poor horses rub and scratch their bellies on the ground so much that they bleed, or reach around and bite their elbows until they bleed, sometimes referred to as sweet itch or Queensland itch. Skin crawling/tingling that drives you nuts is yet another symptom of "Hyperkalemia" (excess potassium).


These skin conditions require a drastic reduction in potassium and an increase in sodium, a decrease in sugar (short or lush grass) consumption and a corresponding increase in mature grass or hay consumption to restore hind-gut health and function. This will kick start B-Vit production (essential for healthy skin), ensure Omega-3's are in the diet with a good quality multi-vitamin and mineral supplement which does not contain potassium. The answer lies in getting the horse into a state of optimal health.


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High Sugar = Lack of Fibre

Insulin resistance/acidosis/laminitis.


Grasses planted primarily to fatten livestock and promote milk production are 'high sugar' grasses. Hay made from wheat, barley, Rye Grass or oats is high in sugar, especially if it has been made prior to seed formation. Sugar levels can be elevated in grasses when they are drought stressed or over-grazed. Sugar levels can sky rocket in the spring when grass shoots away. Grains, whilst they contain some protein, are mainly carbohydrate and therefore oats, corn, wheat and barley contribute to total sugar the horse is consuming. So does any feed containing molasses.


When the input of feed far exceeds the output required for the amount of exercise the horse is doing, problems will ensue! What is happening is we make the mistake of thinking that grass provides enough roughage and fibre, NOT TRUE! Young, green, growing grass is mainly non-structural carbohydrate (sugar and starch). Clover is one third higher in starch than grass. As the grass matures, it develops more stalk and becomes more fibrous (as in roadside grass or standing hay). Then it is great as it is more fibre than sugar.


Food ingested by the horse passes through the small stomach to the 'small intestine' (where carbs are digested). From there it passes through to the HUGE hind-gut, (the caecum and large intestine), which takes up most of the room in the horses 'barrel'. The hind-gut is meant to be chokka full of micro-organisms which are designed to ferment the large quantities of fibre the horse would normally eat. What happens instead is that the excess carbohydrate from the grass/molassed grains diet we force upon them, gets pushed into the hind-gut, where it cannot be digested.


This results in acidosis (low pH) which kills all those good micro-organisms at the same time encouraging an increase in detrimental bacteria and pathogens in the horses digestive system. The ensuring metabolic chaos, compounded by mineral imbalances (especially high potassium), results in inflammation of the laminae of the hoof and there you have it, sore feet and laminitis. In fact the horse/pony can eventually become insulin resistant, which is a similar condition to type 2 diabetes in humans.


Signs of insulin resistance include:


  • Being obsessed with eating, especially grass (you can't keep their head up!),
  • 'Lives on the smell of an oily rag' (get fat easily);
  • 'Cresty' neck,
  • Gets 'pads' of fat behind the shoulders and above the tail,
  • Puffiness around the eyes and sheath,
  • Frequently urinating,
  • Lethargic,
  • Mares don't cycle properly,
  • Drinks a lot,
  • Sore feet (pre-laminitic),
  • Prone to laminitis.


Overweight Horses


It is important to understand that these horses are not just fat, they have a serious metabolic disorder that needs urgent action! They are like diabetic people and suffer from the dysfunction of every major organ system in their body; the circulatory system (especially to the hooves), the digestive system (especially the hind-gut), the reproductive system, the nervous system (including the brain) and the endocrine system. They are an inch away from foundering.


What to do.


These symptoms can be reversed by removing the horse from anything green, especially short grass in spring and autumn (merely restricting grass may not be enough), and feeding plenty of hay that has had much of its sugar content leached out by soaking in a tub of cold water for at least an hour before feeding. The water goes brown and fizzy. You can tip it on your garden. Supplement with a quality vitamin and mineral supplement containing organic chromium and magnesium. Attention to healthy hoof form and as much exercise as possible are equally important.


Prevention is way better than cure.


Please understand that it is primarily a hind-gut problem caused by sugar overload, lack of fibre and lack of exercise. These horses are the equivalent of the couch potato person who lives on junk food. The key to a healthy horse with healthy hooves is to look after the flora in the hind-gut by ensuring the majority of the horses diet consists of coarse, fibrous material such as mature grass, hay, chaffs and beet.


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Fibre Requirements Relative to Lifestyle

Adult horses and ponies.



Table 1.1 - Feed Rate Table




  • Soak hay in water for one hour (to reduce sugar content), discard water and feed immediately.
  • Feed hay without any Perennial Rye Grass, Clover or any of the other bad grasses.
  • Supplement with calcium and magnesium if grazing oxalate grasses.
  • Supplement with extra calcium, magnesium and sodium if grazing rapidly growing grasses, especially in cool, wet, cloudy, frosty climatic conditions. The first shoots to appear after a drought breaking rain will be particularly dangerous.
  • Supplement with sodium to help correct the sodium potassium ratio and help buffer any acid build up, to increase water intake (there must always have fresh drinking water freely available).
  • After approx six to nine months the obese/laminitic horses' metabolism will be returning to normal and they can be fed as 'Idle'. Be extremely diligent about not allowing a relapse.
  • When on any kind of pasture feed a toxin-binder containing natural yeast cell wall extract. For oxalate pastures, in particular a highly absorbable calcium and magnesium supplement.
  • For horses in moderate to intense work, add carbohydrate (e.g. grass and grain) and protein (e.g. soya bean meal, solvent extracted canola meal, sunflower seeds) according to energy requirements (view Table 1.1). Be careful of full fat soy in warm weather as the oil content may go rancid.
  • Avoid sugar and protein overload in broodmares, young and growing horses by supplementing their diet with enough high fibre intake to offset the high sugar content of lush pastures.


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Why Add Fibre?


Adding fibre to the diet of Australian and New Zealand pasture fed horses is vital.


  • It keeps the hind-gut and its resident micro-organisms healthy, preventing sugar overload which causes hind-gut acidosis (sloppy manure), Attention Deficit Disorder (ADD), insulin resistance, metabolic chaos, laminitis,
  • The digestion of fibre has immune-boosting, anti-allergic and hormone regulating effects,
  • The fermentation of structural fibre is a major source of energy,
  • Fibre helps synthesise B-Vits and vitamin K for calmness and good health,
  • Provides fuel for their internal body heater,
  • Creates a water reservoir for proper hydration, especially after sweating, urinating and salivating,
  • Requires more chewing = more saliva, preventing stomach ulcers.


Does your horse eat grass, clovers, molassed feeds and/or grains?


Consumption of grass, Clovers, molassed feeds and grains without sufficient accompanying fibre according to lifestyle will sooner or later result in a vast array of ill-health problems. Symptoms including many of those in the above list (e.g. herd bound, nappy), ravenous appetites, insulin resistance, obesity or ill-thrift, weak, sore feet and laminitis will become apparent.


Green grass which is kept at a young stage of growth by constant grazing does not supply enough fibre in the diet of Australian and New Zealand pasture fed horses.


How Much Fibre?


A 500kg horse requires approximately 2% of his bodyweight per day, i.e. 10kgs per day, 365 days per year. Hay bales vary but this is approximately half a bale. This can be achieved with a combination of hay, chaffs and beet pulp.


NB. A heavy hack of 16.2hh will weigh approximately 550kg, a 14.2 galloway approximately 400kg and a 12.2 pony will weigh approximately 300kg. Take your empty float to a weigh station, then take your horse in your float to the weigh station - this will give you an accurate weight. Alternatively use a weight tape.


If the horse is light in condition, feed according to the weight he should be, not the weight he currently is. If you want your horse to lose weight, soak the sugar out of the hay rather than cutting down his hay. Horses have a need to be eating and chewing sixteen to eighteen hours a day. Long periods without food cause mental stress and stomach ulcers.


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Within the large intestine of the horse, there should be a healthy population of 'good' bacteria, whose purpose it is to breakdown the food further, producing energy-rich, short-chain fatty acids. These bacteria also produce essential B vitamins of which biotin is one, and vitamin K, necessary for just about every function in the body, including healthy red blood cells and optimal function of the nervous system, healthy hair coat and strong hooves.


Signs that a horse is not making enough of his own B vitamins are poor appetite, sour attitude, anaemia, poor hooves and skin conditions. Biotin is one of this large group of vitamins. Everyone is busy supplementing with biotin to improve hooves when all the horse needs is more fibre in his diet so he can make his own. Hooves will not be strong and healthy on a sugar diet!


Anything that upsets digestion, such as a low roughage diet (e.g. springtime sloppy manures caused by acidosis) or increased stress of any kind, will interfere with the horses ability to produce his own B vitamins. It is a good idea to make sure your multi vitamin/mineral supplement has the full range of B vitamins. The range of vitamin B's are water soluble and not stored in the body - you cannot overdose on them.


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Selenium is essential to good health in the horse. It is a trace mineral which helps to make important antioxidant enzymes that have several functions in the horse's metabolism. These selenium containing enzymes provide antioxidant protection in every cell of the horse's body. They also have roles that affect growth, immune function, muscle recovery and reproduction.


Many areas of New Zealand and Australia have soils deficient in selenium, which means unless you are supplementing with it, your horse is likely to be deficient. Too little selenium in the diet is a problem; it's a bit like trying to run a car without oil, causing degeneration of muscle tissue, stiffness of gait and a predisposition to 'tying up'. However, too much selenium is a problem as it is toxic to your horse. This has become more of a possibility since selenium is now added to a lot of feeds.


Annual blood tests are essential, so you know exactly how much to supplement with.


It is best fed in small doses often, as in the organic forms available that you add to a daily feed. For economic reasons, people with multiple horses often resort to the less absorbable, but cheaper, inorganic forms of selenium as in Selmit 1.


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Sunburn and mud fever.


Burnt NoseMany horses with white faces and/or white socks, suffer from 'sunburnt' noses, and/or chronic mud fever. Some get ulcers in their mouths. The first line of thought with mud fever is that it is caused by 'mud'. The first line of thought with scabs on the nose is 'sunburn'. However, the truth is that it can be a very complex issue that doesn't respond to external treatments. This is because the real cause of 'mud-fever' and 'sunburn' is photosensitisation.


This is caused by eating plants which contain certain photodynamic (or fluorescing) pigments. These pigments enter the bloodstream and eventually reach the unpigmented skin of white faces and white socks, where they are exposed to UV rays, where they oxidise, and thereby create oozy sores in the surrounding skin.


Hair LossAffected skin rapidly becomes reddened, painful and raised above areas of adjacent pigmented skin. Serum often oozes through the affected skin to form crusts in the hair. Soon, the dead skin becomes dry and parchment-like, and the hair and white skin slough leaving ulcerated areas that may develop secondary bacterial infections, especially in muddy conditions, hence the name 'mud fever'. Yet the bacterial infection could be secondary to the real cause which is photosensitisation.


Pictured above is a mild case after eating a very small amount (flecks) of Clover amongst her grass hay.


When this occurs on the muzzle, it resembles, but is not sunburn. It is a reaction caused by eating these plant pigments which are exposed to UV rays in the vulnerable unpigmented skin areas. Most commonly affected areas are the muzzles of horses with white faces and white socks as in mud fever.


Mud FeverThis explains why some horses that have 'heaps of white' never sunburn or get mud fever, while others do, chronically and exasperatingly! Plants known to cause this kind of photosensitisation include Perennial Rye Grass (you might have guessed!) Clovers (especially White Clover), Alfalfa, Lucerne, St John's Wort (Hypericum perforatum) and Buttercup. Many horses are grazing pastures that comprise these species. Buttercup also contain a chemical that causes dermatitis from direct contact with it.


Protection from UV rays is a huge help in prevention, however, this is tricky on the legs. There are vast numbers of topical applications for treating mud fever, which 'work' but often on some horses but not others. Quite often, just when you think you've got it beat, hey presto, it's back!


Pictured above right is a mild case of hair loss on the face due to grasses. Some seasons she would lose most of the hair on the sides of her face.


Preventing the horse eating the offending plants is obviously the best option but not always easy. Keep in mind that Rye Grass, Clover and Lucerne hay may also cause skin photosensitivity. It is yet another really good reason to work out ways to change your pastures to encourage other species than those listed above (view Paddocks-Yards-Grasses).


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Head Flicking/Shaking


Head Flicking/ShakingHead flicking/shaking is one of the most heart-breaking, exasperating, baffling conditions to affect horses anywhere. It has been established that it involves the trigeminal nerve in the horses head. The trigeminal nerve originates behind the horse's eye and has branches down to the mouth, nostrils and up to the ears. When this nerve is surgically 'cut' or 'blocked' the symptoms immediately cease but unfortunately, in the case of cutting, the nerve eventually heals up again to some extent after which symptoms are worse and in the meantime the horse has a 'droopy lip'.


People with trigeminal nerve trouble describe 'sharp, electric shock sensations' in their face. It is an extremely painful condition and warrants urgent action (view what to do). Globally, nobody has any idea of the cause of head flicking. Many treatments have been tried, everything from nose nets, to masks, to contact lenses, melatonin, spirulina, drugs such as cyprohepradin, even surgical cutting of the nerve.


Until now, the prognosis has NOT been good for head flicking horses. Often they are turned out only to get worse. When distressed owners see them flinging around the paddock, banging their head on the side of the water-trough or trying to stuff their head in the hedge they are often put down.


A likely cause.


Trials conducted on bad cases of head flicking horses found that if they where left to graze on pasture predominantly rye grass and clover the head flicking would persist and get worse, particularly over spring and autumn. When these same horses where moved onto native grass pasture or 'horse safe pasture' such as Cocksfoot (orchard grass), different varieties of Brome grass, Rhodes grass and Browntop (Bent grass) the head flicking reduced dramatically or stopped all together. It has also been observed that headflicking can be triggered after fertilising with super phosphate or feeding lucerne (Alfalfa). 


Horses affected by head flicking also appear to have photophobia, which causes them to dislike bright light or reflective surfaces. Bright, sunny, breezy days can often be the worst for head flickers and riding on sand arenas which reflect the light are difficult for them. Often these horses can appear fine while walking but as soon as they start to warm up with increased work the increased blood flow can trigger flicking. As with all inflammation the inflammation of the trigeminal nerve increases with exercise.  Head flicking horses can appear to be very unpredictable, suddenly stopping to put thier head down to rub their nose on their leg. Which can become quite dangerouse when at high speeds and with out any warning.


Move head flicking horses onto more navite pasture and take them off the grass at night, eliminate all lucerne out of their diet and feeding lots of horse safe grass hay along with a plain feed of white chaff and soaked beet pulp. Highly absorbable organic magnesium blend and a top quality, well balanced vitamin and mineral mix with added salt will greatly assist affected horses. The idea is to remove the cause at the same time replenishing the horses system with vital minerals.



Lisa Catherwood and Annette Hatherley from Victoria both had chronic head flicking horses. Both Lisa and Annette followed Gotcha Equines instructions and both horses recovered to be happy useful horses. View their case studies.  Learn what to do. The video footage (above left) is a short view of a horse having a flicking episode. You can see the lush Rye Grass and Clover pasture that was causing it.




  • May start with head twitching,
  • Involuntary jerking up and down of the head exactly like a bug has flown up their nose,
  • Suddenly having to rub their nose on their leg, or drag it along the ground,
  • Leaping around trying to 'box' their nose with their front feet,
  • Worse on sunny, breezy days,
  • Worsens with exercise.


Sometimes associated:


  • Photophobia where they can't stand the light,
  • Desperately seek shade, even stuffing their head in the hedge,
  • Eyes and nostrils screwed up, like they have a migraine,
  • Plunging their head in and out of the water trough,
  • Depressed.
  • Runny nose and eyes


Theory on the cause.


Based on strong anecdotal evidence. NB. The science is always five to ten years behind the anecdotal evidence or the hypothesis. Since head flicking coincides with many other health and behaviour issues which occur in the climatic conditions of spring and autumn, it follows that it shares the same fundamental cause. I now believe that head flicking is caused by the pasture spikes in potassium and nitrates which occur in the cool, wet, cloudy, even frosty conditions of spring, autumn and sometimes other times of the year, depending on the weather.


These happen especially when you have Rye Grass and Clover (both are inherently high in potassium nitrates anyway) or any type of pasture when it has been stressed by drought, frosts or over-grazing or when it is in rapid growth mode and when it has been fertilised to increase production. Rye Grass, Clover and Lucerne (or Alfalfa) are all potent triggers for head flicking syndrome because they are also inherently high in potassium nitrate and low in sodium. If your horse isn't eating any grass then you would have to look at your hay as it too can be high in potassium nitrates.




Excess potassium nitrates are ingested with forage. This happens under certain climatic conditions, especially those of spring and autumn. These nitrates (anions) must be eliminated from the body and the means by which this is achieved is that of latching onto calcium and magnesium (cations) and being excreted with them. This leaves the horse's system extremely high in potassium and at the same time extremely low in calcium, magnesium and sodium.


This represents a serious, dangerous electrolyte imbalance. The correct sodium:potassium ratio and adequate amounts of calcium and magnesium are vital for normal nerve function. In head flicking, somehow this acute imbalance causes temporary (maybe sometimes permanent?) damage to the trigeminal nerve which leads to the involuntary firing characteristic of the head flicking syndrome. Reversing this syndrome therefore involves removing the cause (the offending pasture/hay and other feeds aggravating to the condition) while simultaneously correcting the mineral imbalances.


What To Do.


Arrange somewhere for the horse to come off the grass at night with no grass - a yard, stable or a sprayed out piece of the paddock, somewhere you can completely control your horse's diet. Feed ad lib low nitrate hay (no Rye, Clover, Lucerne, Sorghum, Oaten). Feed soaked beet with plain chaff for the purpose of replenishing with the organic minerals (learn more through the Gotcha Feed Plan) and extra salt (5-10gms per 100kg).


Over a period of 8-12 weeks the head flicking will go away. This can be somewhat sporadic. In other words there may be a few bad days in there but eventually you will hardly feel a flick. You will have your lovely horse back!


NB. Never make a sudden change to the diet, as in 100% grass to 100% hay. Introduce the night yard slowly over a period of a 2-3 weeks, replacing with more and more hay.


Confusing syndromes.


Head-shaking. This has the same cause and treatment as head flicking. It affects the branch of the trigeminal nerve that goes up to the ears. The horse will frequently shake his ears while you are riding, sometimes cocking his head to one side and sticking one ear out and down.


Touchy around the ears (ear-shy). This shares the same cause and responds to the same feeding regime as for head flicking. Lots of people think that their horse has been beaten around the head because they are so touchy around the ears. Not so - they are affected by the same mineral imbalances, it is just showing up in a slightly different way. Naturally, haltering and bridling can be an issue if the horse is touchy around the ears. These horses are very prone to PULLING BACK violently if they are tied up or restrained in any way. It is best to NOT tie them up at all until they have come right. Besides the fact it is dangerous, a violent pull back can cause permanent damage to the horse. Don't worry when they are back to normal as they will tie up just as well as before.


Rhinitis. Lots of horses suffer from a condition where the nasal membranes become inflamed and even ulcerated. Swabbing for herpes comes back negative. This is caused by inhaling fungal spores and pollens. The horse will do a lot of snorting and head-tossing especially at the start of the ride. Rhinitis does not respond to the same treatment as for head flicking.


For experiences by owners with horses with head flicking, please read the following testimonials:




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