First things first, you need to rule out potential health issues causing weight loss or failure to thrive.  Consider a visit by your vet to do a general health check, do blood work and even scope the gut. 


  • Rule out medical and environmental causes of weight loss.
  • Remove from diet all:
    • grains (wheat, oat & barley)
    • poly-unsaturated oils (vegetables, canola, rice bran, sunflower etc)
    • excess salt (preferably leave a Himalayan rock salt in the paddock)
    • sugar additives (don’t forget sugar has many names)
  • Switch to safe feed options of cracked lupins, beetpulp, copra and quality lucerne hay & chaff where possible.
  • Add a fully balanced vitamin and mineral supplement that is also both organic & chelated where possible such as Flowers Gold by Wattlelane Stables.
  • Feed a minimum of 1.7% of body weight in dry feed (pasture, hay, chaff and hard feed).

Medical and environmental reasons that may interfere with healthy weight gain include but may not be limited to:

*             Parasites. Ask your vet to do a faecal count to rule out a hidden worm resistant problem.  Rotate worming types seasonally.   Ask your vet for advice. 

*             Teeth.  Sharp molars, uneven teeth, stuck caps in young horses and mouth ulcers can dramatically reduce the efficiency of nutritional uptake as well as amount of feed consumed.  Dentistry should be done yearly by a qualified and experienced expert.

*          Gut health issues may cause pain, reducing the horses will to eat.   Loose droppings cause significant loss of nutrition and electrolytes.

*             Diseases of the liver and kidney can cause weight loss from excess protein excretion rather than utilisation.  Other diseases worth testing for include Cancer and Endocrine disorders such as Pituitary Pars Intermedia Dysfunction (PPID) known as Cushing’s Disease, Stringhalt and equine motor neuron disease.

*             Insufficient roughage to generate heat to stay warm causes the body to shiver away fat storage.  A horse should be fed 1.7% of their ideal body weight per day in roughage.

*             Weight loss in old age can be caused by parasite damage in the past, poor dental conformation, inability to stay warm in Winter (without adequate shelter or rugging they will not hold weight successfully) and poor gut microbes as a result of a long term wrong feed induced microbial die off.

*          Volume, type and quality of feed are significant reasons for either easy weight gain or weight loss.  Feeding poor quality hay, grains, too much salt and sugars along with polyunsaturated oils and too much Omega 6 can all set a horse up for poor gut health leading to weight loss.  Vitamin E and calcium deficiency can cause weight loss.  Excess Phosphorus can deplete calcium and potentially cause weight loss.  Insufficient volume per body weight will lead to weight loss. 

*              Toxicities.  Toxic exposure (such as iron, copper and lead) can be from consuming pasture grown on hazardous soil (soil testing is extremely important) can lead to weight loss, muscle wastage and diarrhea.  Toxic weeds ingested can also cause weight loss.  Horses can suffer from thiamine deficiency when ingesting bracken fern.

After ruling out health conditions, you can focus on feeding the right foods for healthy weight gain.

We will begin with the simple and effective feed techniques developed by The Nude Horse after a decade of research into what a horse really needs to be healthy and avoid foods that induce disease or ill thrift.

What NOT to feed   

A horse is designed to graze 24/7 on forage, predominately grasses and select plants, shrubs and trees.  Horses in captivity are often fed premix hard feeds that contain foods that their gut was never meant to intake in large volumes.  Common feed inputs known to cause health problems include grains (wheat, barley, oats etc), sugar (molasses & sugars in its many hidden forms), polyunsaturated oils (vegetable, canola, sunflower, safflower, rice bran etc), over feeding salt and often poor quality.  Excess salt causes stress to kidney function, in turn reducing protein absorption that ultimately can lead to kidney failure. Sunflower seeds are extremely high in Omega 6, this alone can cause poor health. 

Combining several premade hard feeds and various feed supplements will throw minerals ratios out, causing toxicities and depletions as they are all interconnected.  Each mineral interacts with other another mineral(s), so either supports the body absorption or is an antagonist to another mineral – stops it being absorbed.  The visible results are often seen first as a dry brittle and bleached coat colour followed by weight loss and muscle wastage.  It is important to note when it comes to vitamins and minerals ‘more is not better’.  Vitamins and minerals intake must be fed within safe parameters for optimal weight gain.  See under heading “Feed Supplements (vitamins and minerals)” below to assist in finding the right supplements.

The trouble with grain

Most grains are high in the polysaccharide carbohydrates of sugar and starch (NSC).  This type relates to metabolic disorders. During the digestive process, both sugars and starches are turned into the sugars.  Horses have a limited capacity to digest substantial amounts of sugar and starch in the stomach and small intestine.  The excess supply of sugar and starch travels through the small intestines and on into the hindgut where the trouble begins.  An increase of sugar fermentation creates lactic acid.  Lactic acid lowers the pH causing an acidic environment, this in turn kills off the good microbes.  The dead microbes give off endotoxins that now enter the blood stream, this chain reaction often culminates in poor gut health, ill thrift (or obesity) and potentially laminitis.

Grains too are typically dominant in insoluble fibre – these type of fibre pass through the entire digestive tract unchanged so little calorie uptake can occur. 

Most pre-mix horse feeds appeal to the buyer (looks and smells great), and likely include some or all the above ingredients, these types are feeds are best avoided when trying to gain weight and bring your horse back into health.  Additionally, many premix feeds deliver insufficient qualities of necessary vitamins and minerals, and quickly go out of balance when fed in different volumes than recommended.  Often vitamin and minerals are poorly revealed on the packaging, so you can never be sure what your horse is consuming by way of nutrition.  To gain weight successfully, correct daily nutrition is paramount.

Safest hard feed options

Switching to carbohydrates highest in soluble fibres improves energy and supports healthy gut microbes, these in turn directly influence the horse’s total health and wellbeing – including the ability to put on healthy weight and maintain it.

Readily available base feeds high in soluble fibre are lupins, beet-pulp and copra. Soluble fibre dissolves in gastrointestinal fluids, transforming into a gel like substance that is easily digested by the good gut bacteria releasing energy and calories.  Feeds containing soluble fibre are less likely to cause spikes in blood sugar levels and even prevent them.

Good oils with healthy Omega 3:6 ratios are hemp seed oil and fish oil.  Coconut oil is a saturated fat with numerous health benefits.  Coconut oil is a safe and effective feed option for weight gain.  Feed up to ½ cup daily for added calorie intake.  Flaxseed is also beneficial for the Omega 3 content, however the absorption is limited to 5-10% of available EPA and DHA, so more is necessary to meet dietary requirements.


Healthy weight gain hinges on quality protein uptake and absorption.  A bag of horse feed may boast a high protein percentage; however, the types of protein are more important than the total percentage.  Remember proteins are really amino acids, so you need to look at the amino acid profile to know if it contains the right kind of amino acids.

Our top-ranking recommendation for quality protein feed suitable for growing horses, weight gain and working horses is lupins, preferably cracked and soaked for 1-5 hours prior to feeding.  We also recommend combining lupins and copra to offer an excellent array of quality protein (amino acids).

Worthy of discussion is Soya bean products, likely listed as soymeal.  Soymeal sports the highest of all the proteins in the chart above.  However, we recommend not feeding soymeal, or if unavoidable, feed infrequently or in smaller portions, due to it’s many negative attributes.  See our article “Base Feeds” to read about the risks associated with feeding Soy products.

Feed supplements (vitamins and minerals)

There are a barrage of animal feed companies offering every options of feed supplements that contain vitamins, minerals, amino acids, herbs, extracts and spices.

Do you need to add so many of these?  Not necessarily.  You have just read that the right base feeds already contain excellent amino acids, so skip on these unless you are dealing with a health issue that calls for a specific amino acid (usually anxiety issues benefit from some amino acids).  Herbs and herbal extracts are useful and beneficial (anxiety issues call for these) generally feed only when required for treating a specific health condition.  Some spices like turmeric are beneficial for their anti-inflammatory attributes, but again unless you have a health issue that calls for this, it too may not be necessary.

Vitamins and minerals however are a must for improving health and gaining weight.  Horse in captivity often rely on limited pasture, hays and hard feeds so are usually quite deficient in vitamins and minerals without the right supplementation.  A vitamin and mineral deficiency can be the sole cause of poor weight.  When the body does not receive the necessary nutrients to heal, repair and function then total health deteriorates.

Choosing the right feed supplement is necessary to meet dietary needs successfully.  The choices are almost endless.  Some are expensive, others suspiciously cheap.  Often price reflects quality and the array of ingredients, but you still need to read the analysis and compare as some are purely an expensive brand.  If a label delivers a confusing description such as minerals in their % form per kg, then they never meant for you to know the daily ration offered.  If a feed supplement states only that it contains their ‘signature vitamin and mineral blend’ you can bet it is a poor offering.

The Nude Horse recommends a fully balanced comprehensive vitamin and mineral supplement such as Flowers Gold by Wattlelane Stables that is both chelated (minerals bound to an amino acid to enable complete absorption) and organic (the body recognises as a food source, rather than a potential toxin as synthetic nutrients can).  Feeding the recommended daily ration along with your own healthy choice of base feed options ensures the correct nutrients are delivered whether you are trying to assist weight gain or keep at a maintenance level.

An underweight horse may be suffering from gut ulcers, loose manure or recovering from illness with antibiotic support, they will benefit greatly from a high-quality gut microbial pro biotic supplement.  The feed supplement Gut Centric is known to supply the most potent and broadest variety of microbial species available, coupled with pre-biotics to encourage re colonization.  Gut Centric requires a single 3- week course to assist healthy gut microbial recovery.

The final aspect to successful weight gain is volume of feed.  Firstly, work out what your horse’s ideal weight should be.  Then multiply this by 1.7%, this will give you the kilograms of dry feed your horse needs each day.  To weight accurately, purchase a cheap luggage scale from a Discount Store (likely $10 or less) or scales you hold to weigh fish from a fish and tackle store. 

A minimum of 70% of daily required feed weight should be in grass grazing or quality hay, we recommend lucerne for its nutritional profile and low sugar content.  The remaining feed by dry weight can be made up with an equal split between cracked lupins, beet pulp, copra and chaff, to this add your choice of quality vitamin and minerals.  Ensure the correct water volume is added to these base feeds to ensure proper hydration is maintained. 

You can add 1 TBSP of Hemp seed oil or fish oil to deliver quality bio available Omega 3 to help correct the over supply of Omega 6 found in many hard feeds.  Coconut oil can also be added for additional good calories, up to ½ cup per day.  Flaxseed also contains Omega 3, but only 5-10% of this is bio available, so you need to feed a suitable amount to be beneficial. 

Always leave a Himalayan salt rock in the paddock or stable for electrolyte replenishment when necessary, generally there is no need to add extra salt to a horses hard feed unless undergoing a heavy workload or in a hot climate where the horse is daily sweating profusely.

See our website to learn more about equine nutrition, how to weigh your horse, proteins, feeding the foal and growing horse and much more.

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