Feed for underweight horses: Build condition effectively

You feed regularly. Your horse gets its feed, hay disappears from the net, yet you still see prominent ribs, a weak topline and a lack of "body". This is one of those moments when you start wondering whether you are doing something wrong or simply have a horse that "is just like that".

In practice, the problem very often is not that the horse receives too little of everything in general. The problem is that it receives the wrong things, in the wrong order or, for some reason, its body cannot make good use of the feed. This is precisely why feed for underweight horses should not be chosen on the basis of "I will buy something higher in calories and add more oats".

As equine nutritionists, we often see this pattern. You mean well and increase cereals; the horse becomes more nervous, droppings can become looser, appetite sometimes falls, and weight does not increase as it should. It is frustrating, but it can be put right.

Introduction: When your horse is too thin despite your efforts

It usually starts similarly. Your horse eats, works fairly normally and may even seem cheerful, but photographs and grooming reveal that its condition is not what you expect. Or the reverse happens. After illness, a change of stable, a more intensive season or winter, your horse has not rebuilt condition as it should.

In these situations, owners usually hear two pieces of advice. The first is "give more oats". The second is "that is just its type". Both can delay a good solution.

An underweight horse does not simply need more food. It needs a well-designed nutritional strategy. First establish why it is losing weight or failing to gain it. Then improve the foundations. Only at the end do you choose a specific feed for underweight horses and any additions.

Sometimes the change that really helps starts with better-quality hay, a dental assessment and a calmer feeding plan rather than a bag of hard feed.

If you feel you have tried everything and your horse still looks too thin, approach the issue like a puzzle. Every piece matters: health, stress, forage quality, concentrate type, meal frequency and the pace of change. When these elements work together, weight usually starts moving in a safe direction.

Why is my horse thin? Common causes of being underweight

Low bodyweight rarely has just one cause. Much more often, several small problems build up together over weeks. So rather than immediately buying new feed, take a brief, honest look at the situation.

Health first

If your horse loses weight despite having an appetite or loses condition without an obvious change in workload, the first step should be a health check. Teeth, parasites and the digestive tract are particularly important.

A horse with sharp dental edges may spend a long time "eating" but do so inefficiently. It grinds hay less thoroughly, some fibre passes through the digestive tract less well prepared for digestion, and you see an empty manger and assume everything is fine.

Gastric problems can produce a similar picture. Your horse may approach food, walk away, fuss, eat more slowly or become selective. In some horses, being underweight is one of the first signs that the digestive system is uncomfortable.

Signs worth noting before speaking to your vet:

• Appetite changes: your horse eats more slowly, leaves feed or picks out only the tastier parts.
• Poor chewing: dropping mouthfuls, taking longer to eat hay or reluctance to eat harder feed.
• Changes in droppings: occasionally looser droppings, less well-formed balls or an unusual smell.
• Reduced willingness to work: your horse seems to function but "fades", tires more quickly or is irritable.
• Recurring discomfort: symptoms that may suggest digestive problems.

Management mistakes that are easy to overlook

Not every thin horse is ill. Sometimes the environment and feeding arrangements are responsible. A lower-ranking horse in a herd may simply lack peaceful access to hay. In a stable, it may eat too quickly and then spend a long time without fibre. In winter, cold, wind and the extra energy needed to keep warm can add to the burden.

Owners often focus on hard feed while overlooking the fact that their horse lacks comfortable access to good forage for much of the day. Even the best feed for underweight horses cannot do all the work then.

If your horse is fed correctly "on paper" but still loses weight, check whether it actually eats what its feeding plan says.

The diet itself can also be the problem

Sometimes a horse receives enough calories, but not in a form it can use well. A typical example is a cereal-based diet with mediocre hay. The manger is full, but the horse lacks a stable fibre foundation and its digestive system is under strain.

A short checklist helps identify the most common mistakes:

• Hay quality: it smells fresh, is readily eaten and is neither woody nor dusty.
• Forage availability: your horse does not have long gaps without hay.
• Matching the ration to work: a competition horse, senior and horse recovering from illness will not respond identically.
• Type of energy in the ration: plenty of cereals does not always mean a well-balanced diet.
• Pace of change: frequently mixing feeds, sudden quantity changes and random additions make results difficult to assess.

If anything on this list raises doubts, pause and put the foundations in order before changing to another bag of feed.

Foundations of an underweight horse's diet - energy is not everything

Owners of thin horses most often look for "weight-gain feed". That is understandable, but it is worth reversing your thinking. First build a diet the horse's digestive system can use well, then increase its energy content.

Hay is the foundation, not an addition

Under Polish feeding conditions, hay remains the foundation for rebuilding weight. Industry publications state that an adult horse should receive at least 1.5 kg of hay per 100 kg bodyweight daily, with this amount increased for an underweight horse. For a horse weighing 500 kg, this means at least 7.5 kg of hay daily. The same publication states that an adult horse's average maintenance requirement is around 78 MJ of energy daily, equivalent to roughly 12 kg of hay, rising during hard work to around 150 MJ, or around 23 kg of hay. These figures clearly show that fibre, rather than concentrate, is the starting point [hay and energy recommendations for underweight horses].

This is where many owners go wrong. If your horse receives little hay or poor-quality hay, adding hard feed is like patching a roof when the foundations are cracked.

Why simply adding "more calories" is not enough

A horse can gain fat but still look poor. It then lacks topline, hindquarters, neck and overall muscle quality. A diet for an underweight horse should therefore support both bodyweight and tissue rebuilding.

In practice, four pillars matter:

• Fibre: stabilises intestinal function and provides a safe energy foundation.
• Good-quality protein: supports muscle rebuilding and recovery.
• Fat: increases the ration's energy density without excess simple sugars.
• Vitamins and minerals: without them, the body uses other nutrients less effectively.

Comparing energy sources in your horse's diet

Protein builds, fat helps and additions complete the picture

If your horse is thin after illness or an intensive season, or has a weak topline, simply "fattening it up" is not enough. It needs nutrients to rebuild muscle. Look at feed ingredients more broadly than energy alone.

A well-formulated feed for underweight horses usually contains fibre, fat sources and readily available protein. This combination produces more predictable results than adding random extras to oats.

A horse that needs to gain weight safely should eat in a way that keeps its gut settled, rather than simply making the manger look "richer".

In practice, remember a simple distinction. If your horse has a good belly but a weak topline and little muscle, the issue may be overall ration quality rather than insufficient energy. If it is clearly thin everywhere, we usually start by increasing forage nutritional value before adding an appropriate concentrate.

Which feed for underweight horses? An overview of VETfactory options

This is where a costly mistake is easiest to make. You see a thin horse, reach for the first feed promising "weight gain" and increase the portion. Your horse does receive more calories, but not always more of what it actually needs to rebuild its body safely.

Treat feed selection as drawing up a plan rather than a quick fix. One horse needs conditioning feed. Another benefits more from a balancer. A third only improves its appearance when more fibre and better meal structure enter the ration.

Conditioning feed when the ration needs greater nutritional value

If your horse readily eats hay but remains thin throughout its body, we usually look for feed providing more energy in a reasonable volume. Good conditioning blends do not rely solely on a high cereal content. They combine energy with fibre, fat and ingredients that help keep the digestive tract more settled.

In practice, mixes or pellets with added fat and fibrous ingredients such as alfalfa or sugar beet pulp work well. This is closer to adding "longer-burning fuel" than another scoop of oats. VETfactory's range includes conditioning feeds in this group, chosen for horses:

• after losing condition,
• after a period of poorer nutrition,
• working harder,
• with a fast metabolism.

The label matters here. If the bag promises "weight gain", also check the ingredients and form of energy.

A balancer when your horse needs a better ration rather than a bigger portion

Some horses look thin because their overall ration lacks balanced protein, vitamins and minerals, rather than because they receive too little hard feed. This is common in horses that eat reasonable hay and have an appetite, yet struggle to build topline and develop "fullness".

A balancer makes sense in this situation. It is a small portion with a high concentration of nutrients. It acts rather like the missing puzzle piece. It avoids unnecessarily increasing meal volume while helping your horse use what it already receives from hay and its base feed.

A good example is Spillers Gro N' Win, worth considering when your horse needs better ration balance rather than a heavier blend. We often choose this approach for horses:

• that become excitable with more hard feed,
• that are fussy and eat small portions,
• with an underdeveloped topline but no major loss of overall bodyweight.

Fibrous products when you want better digestion and meal quality

For many underweight horses, improvement starts with a seemingly simple step. A meal needs more "chewing" and less "quick swallowing". Fibre acts as the calm foundation of the whole ration. It extends eating time, supports salivation and helps distribute hard feed more effectively within the digestive tract.

Alfalfa chaffs, fibrous blends and products based on fermentable fibre therefore often make more difference than another concentrate. VETfactory's range includes support such as Spillers Alfalfa Pro, which can be used to:

• improve meal structure,
• increase the ration's fibre content,
• make oil or supplements easier to give,
• extend eating time.

This is particularly important for horses that bolt their food or become stressed at feeding time. The same ration can work differently when your horse eats calmly rather than hurriedly.

Fat and energy additions, but only on a sound foundation

Some horses cannot manage large portions of hard feed. Increasing the ration's calorie content through fat can then help. It is a practical tool, but not the first step.

First we organise hay, base feed and ration balance. Only then do we add oil or another energy supplement. If your horse has dental or intestinal problems, or eats too little forage, fat alone will not solve matters.

The simplest rule is this: choose feed for a thin horse according to the cause of its low weight, rather than the sight of ribs alone. If the horse is thin throughout, the ration usually needs greater nutritional value. If muscle and topline are mainly lacking, we more often improve protein quality and balance. If thinness comes with diarrhoea, poor appetite, recurring colic or rapid weight loss, changing feed bags alone is insufficient and veterinary consultation is needed.

Introducing changes safely and building weight step by step

Even carefully chosen feed for underweight horses can cause harm if introduced too quickly. Haste can be the worst adviser with horses. You want to help immediately, so increase portions from one day to the next. The digestive system does not appreciate this.

Polish publications emphasise that excess starch from grain is not a safe route to weight gain. Fermentation of large quantities of starch acidifies the hindgut, harms beneficial bacteria and can lead to colic or laminitis. Feeds based on fibre, fat and readily available protein are therefore recommended, because simply increasing cereals can worsen your horse's health 

How to start without chaos

Choose one main change first. This could mean improving hay, introducing conditioning feed, adding fibrous chaff or using a balancer. Do not change everything at once, because you will not know what actually helped.

A good approach looks like this:

1. Check your starting point
   Assess your horse with your hands as well as your eyes. Pay attention to ribs, topline, hindquarters and neck. Also record appetite, behaviour and droppings consistency.

2. Organise hay and the feeding routine
   Your horse should have the most consistent possible access to forage. Long gaps between meals make rebuilding harder.

3. Introduce new feed slowly
   Change the ration gradually over at least 10 to 14 days. This gentle transition reduces the risk of digestive upset.

4. Divide hard feed into smaller portions
   Several smaller meals are better than one large ration. This is simply easier on the gut and usually better tolerated.

What to observe so you are not working "blind"

Owners often look only at weight or ribs. Yet progress is visible more broadly. Appetite may improve first, your horse may settle while eating and use its back better, only looking fuller later.

Pay attention to:

• eating speed,
• willingness to eat hay,
• droppings quality,
• calmness at feeding time,
• changes in topline and hindquarters,
• whether your horse becomes overly excitable after meals.

The best results come from feeding that makes your horse look and feel better. Not simply "have more belly".

An example of a practical approach

Suppose your horse is thin but readily eats hay. It is more sensible to ensure the forage is genuinely good quality first, then add a feed or supplement that increases energy density and supplies building nutrients. You do not need to move straight to heavy cereal feeding.

If your horse is fussy, has a sensitive gut or responds poorly to more starch, approaches based on fibre, fat and easily digested ingredients usually work better. This may look less dramatic in the first few days, but is usually safer and more stable.

The most common mistakes are:

• adding oats without a plan,
• increasing portions too quickly,
• failing to monitor your horse's response,
• ignoring digestive tract signals,
• expecting immediate results.

Building weight is a process. If you want lasting results, your horse's body needs time to make real use of the change.

When to use supplements: Support from TRM, AniVero and Equine America

A supplement does not replace a good ration. If your horse receives too little hay, unsuitable feed or has a health problem, no powder will "sort it out". But there are situations where targeted supplementation really makes sense.

When digestion is the problem

If your horse has a sensitive digestive tract, has had antibiotics, sometimes has poorer appetite or uses feed less effectively, digestive support can be very sensible. Owners then often choose stomach and intestinal products, for example from TRM, including options associated with gastric support such as TRM GNF.

This type of supplement makes sense when:

• your horse shows tension or discomfort when eating,
• there is a history of digestive problems,
• weight rebuilding remains slow despite ration adjustments,
• your vet suggests digestive tract support.

When you want to support muscle rather than weight alone

Some horses gain a little "volume" but still look flat and poorly muscled. Supplementation can then support what energy alone cannot achieve. In practice, products with amino acids and ingredients associated with muscle function and recovery can help.

In this group, owners often consider brands such as AniVero or Equine America, particularly for horses:

• returning to work,
• that are older,
• after losing form,
• needing support for muscle quality.

This is no shortcut. A supplement supports the process, but only when your horse has the foundation of a well-designed diet and appropriate exercise.

Supplements are precision tools. They work best when used for a specific problem rather than "just in case".

When else to consider them

In underweight horses in training, more than one difficulty often overlaps. Your horse works, sweats, sometimes drinks too little and can be more nervous. Extra support may then address hydration and post-exercise comfort as well as digestion or muscles.

Sensible questions before buying a supplement are simple:

• Exactly which problem do I want to support?
• Is the base ration already in order?
• Do the symptoms need a vet first?
• Can I assess the effect after introducing the product?

If you do not yet have clear answers, refine the basic feeding first. A supplement should strengthen a well-designed plan rather than replace diagnosis or feed.

Conclusion: Your horse in ideal condition and warning signs

You return to the stable after several weeks of gradually improving feeding. Your horse eats more willingly, its ribs are less noticeable and its coat looks better. This usually means the plan is working. Because the whole system has finally started working together, rather than because one "powerful" feed appeared.

Rebuilding condition in a thin horse resembles building a house from its foundations. First check whether the body has resources to use and whether anything is blocking recovery. Only then add feed that supplies energy without upsetting digestion. Your horse then gains weight, uses nutrients better and functions more calmly.

Briefly, keep five things in mind:

• Look for the cause, not just a solution in a feed bag. Dental, parasite, stomach, stress or management problems often cause weight loss.
• Build on fibre. Good hay, appropriate feeding arrangements and feeds based on safe ingredients work better than hurriedly adding large quantities of cereals.
• Do not try to "fatten up" your horse with oats. Excess starch can worsen digestion, excitability and comfort during work.
• Assess the whole horse. Chest circumference and visible ribs matter alongside appetite, droppings, attitude to food and back and muscle quality.
• Introduce changes gradually. Your horse's digestive tract works best with a predictable routine.

This gives you a simple guide: if your horse is thin but eats, has energy and normal droppings, and the problem developed gradually, ration adjustment and observation can often be the starting point. If weight loss is sudden or accompanied by clear discomfort, changing feed alone is insufficient.

Warning signs requiring a vet without delayinclude sudden weight loss, loss of appetite, colic signs, lethargy, tiring quickly, diarrhoea, difficulty taking food or pain when eating. Feed does not replace diagnostic investigations in these situations.

A well-managed horse does not change overnight. It changes steadily. It starts eating better, digests more comfortably, gains body more evenly and does not simply "swell" around the belly. That is the aim of safe weight building.

If you want to choose feed for underweight horses, a balancer, chaff or an addition supporting digestion and rebuilding condition, explore VETfactory's range. Start by calmly assessing your horse's situation and comparing products by ingredients, method of administration and specific nutritional purpose.