Horses First, Equine Emergency First Aid Training

05/09/2026

05/07/2026

Part 3: Supplementation, dosing, and what actually works

When a horse is deficient in vitamin E, supplementation is recommended regardless of whether clinical signs are present.

However, not all vitamin E supplements are equal, and this is where things often go wrong.

There are two main forms of vitamin E used in equine supplements.

Synthetic vitamin E, often listed as all-rac-alpha-tocopherol, is less bioavailable and not as effectively utilised by the horse.

Natural vitamin E, listed as d-alpha-tocopherol or RRR-alpha-tocopherol, is significantly more bioavailable and is the preferred form for supplementation.

Within natural forms, there are also differences in formulation.

Powder or pellet forms are typically esterified, which improves shelf life but requires additional processing in the horse’s digestive system before absorption.

Liquid formulations are water-dispersible and generally result in a more rapid increase in blood vitamin E concentrations, often within 24 hours. These are particularly useful when actively correcting a deficiency.

Current NRC daily recommendations for vitamin E in horses are 1 -2 IU/kg body weight. This means maintenance levels can be anywhere between 250-1000IU per day depending on the size of the horse or pony.

In clinical cases of deficiency where signs are present, doses around 5,000 IU per day for a 500 kg horse are commonly used, although requirements can vary depending on baseline levels, underlying disease, and individual response.

Follow-up blood testing is important to ensure that supplementation is achieving the desired increase in vitamin E concentrations.

❓ A common question is whether horses can receive too much vitamin E.

In humans, very high doses can interfere with vitamin K metabolism and affect blood clotting. It is not yet clear whether the same effect occurs in horses, and this is still being investigated. However, it reinforces an important point.

More is not always better.

This is another reason why supplementation should be targeted and guided by testing, rather than adding products in without a clear plan.

It is also important to recognise that some horses may have impaired absorption of fat-soluble vitamins, which can result in an inadequate response to supplementation. In these cases, further investigation is warranted.

Long-term, the most effective way to maintain adequate vitamin E status is regular access to fresh pasture. However, for many horses, particularly EMS horses, this is not possible.

This means supplementation and monitoring become essential parts of managing both metabolic health and muscle function.

If your horse is on restricted pasture, on a hay-based diet, or struggling with muscle development, vitamin E status is something that should be considered as part of a broader clinical assessment.

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05/07/2026

Part 2: Vitamin E & The EMS Horse

If you have an EMS horse or pony, you are often doing exactly the right thing by restricting pasture access to reduce non-structural carbohydrate intake and minimise laminitis risk.

But there is an important consequence that is often overlooked.

Pasture restriction also removes the horse’s primary source of vitamin E.

This creates a very common scenario where horses are managed correctly for insulin dysregulation, but inadvertently become deficient in vitamin E.

Many of these horses are maintained on hay-based diets, sometimes with soaked hay, further reducing nutrient content. While this is appropriate for metabolic control, it significantly increases the risk of inadequate vitamin E intake.

In practice, I see this frequently in horses that are:

- On long-term pasture restriction
- Maintained on hay only diets
- Not receiving targeted vitamin supplementation
- Struggling to build or maintain topline

Vitamin E deficiency in these cases can contribute to muscle weakness, reduced performance, and difficulty developing or maintaining muscle mass, even when energy intake appears adequate.

It can also complicate the clinical picture in ridden horses. Horses may be assumed to have training or fitness issues, when in reality there is an underlying nutritional deficiency affecting muscle function.

The only reliable way to assess vitamin E status is through blood testing.

We can measure serum or plasma vitamin E concentrations. The sample must be handled and prepared carefully to obtain an accurate result as Vitamin E levels can be affected by several external factors. Interpretation should always be made in the context of the individual horse, their diet, and clinical signs.

👉 Get in touch with us using the booking link below if you’d like to get your horse’s Vitamin E levels checked.

Stay tuned for tomorrow’s post about supplementation - what works and what doesn’t.

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05/07/2026

Part 1: Why vitamin E matters more than you think**

**This is the first of a 3-part educational series on vitamin E in horses.**

Vitamin E deficiency is one of the most overlooked problems in horses.

In almost all mammals, Vitamin E is essential for the integrity and optimum function of several systems in the body, including nervous, immune, reproductive, muscular and circulatory systems.

Vitamin E is not just another vitamin. It is a potent antioxidant that protects cell membranes from oxidative damage. Importantly, vitamin E levels are associated with the maintenance of normal muscle and nerve cell function.

Horses rely almost entirely on fresh green pasture for vitamin E intake.

Once forage is cut and dried into hay, vitamin E levels decline rapidly. By the time hay is fed, the vitamin E content is often negligible. To make matters more challenging, the vitamin E added to many feeds is synthetic and has significantly lower bioavailability compared to natural forms.

This means many horses on hay-based diets are likely not meeting their requirements, even when their diet appears otherwise balanced.

Importantly, vitamin E is not stored efficiently in the body. Horses require consistent daily intake to maintain adequate circulating levels.

Deficiency does not always present with obvious clinical signs early on. Instead, it often shows up as subtle issues such as:
▪️poor topline
▪️reduced muscle development or muscle wasting
▪️underperformance
▪️weakness

By the time more significant signs develop, deficiency may have been present for some time.

Stay tuned for tomorrow’s post, specifically tailored for horses with EMS.

🩺 Contact us on 0427 072 095 or book an appointment online:
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04/10/2026

Too often we chalk bad behaviour up to a personality “flaw”. Very likely your horse is trying to tell you something else, we just need to listen.

04/02/2026

It is very important to pause and listen to what your horse is trying to tell you.

Knowing what is normal behaviour for our horse helps us recognize when something changes.

Horses are a prey animal so very often their signs of discomfort and distress can be subtle.

03/27/2026

Can’t make it to location for an Equine First Aid Course?

Did you know that we can teach a theory only condensed course online.

Touch base to find out more!