Expert guide for owners of horses prone to eczema (including those in the early stages), build-up protocol for spring.
Summer eczema feels like a problem of spring and summer: as soon as the first insects appear, you see an increase in itching, restlessness, and rubbing. However, the body's overreaction is rarely determined in April or May. What you do in winter counts. Not because winter is necessarily a risky season, but because this is often the time when you do have the rest and time to strengthen the foundations: intestinal flora, intestinal barrier, and immune balance.
In this expert guide, we take a clinical look at the mechanism behind that foundation. You will gain insight into the role of short-chain fatty acids (SCFAs), with a special focus on butyrate, and you will receive a practical building protocol that you can use in the spring. No bold claims, just a well-founded approach that often makes sense in practice for horses prone to eczema.
In case of serious or persistent symptoms (such as prolonged diarrhea, weight loss, signs of pain, or severe inflammatory reactions), always consult your veterinarian.
The intestinal flora, also known as the microbiome, is the collection of microorganisms in the gastrointestinal tract. In horses, the hindgut, consisting of the cecum and colon, plays a particularly important role: this is where roughage is fermented. This process produces energy, but also substances that communicate directly with the intestinal wall and the immune system.
This is relevant for horses prone to eczema because summer eczema is rarely just a "skin issue." It is an immune response to stimuli such as insect saliva. The extent to which the body reacts calmly or strongly is often related to the overall stimulus balance in the entire body. The intestinal barrier, susceptibility to inflammation, and immune regulation play a role in this as risk factors.
When the microbiome ferments fiber and residual carbohydrates, short-chain fatty acids (SCFAs) are produced, primarily acetate, propionate, and butyrate. SCFAs are not byproducts for our horses, but functional nutrients: they are both fuel and signaling substances for the gut and the immune system.
That is precisely why "healthy gut flora" means more than just "no diarrhea." It is about stable fermentation that nourishes the intestinal wall and creates an environment in which the immune system can function normally.
Butyrate receives a lot of attention in the literature because it affects multiple layers simultaneously. First of all, as an energy source for our horses and for the intestinal wall cells. Intestinal wall cells renew quickly and have high energy requirements; in other animal species, butyrate is described as a substantial fuel for colonocytes and linked to a well-functioning intestinal mucosa.
In addition, butyrate is strongly linked to the barrier function of the intestinal wall. A barrier that closes properly means that the immune system is less often unnecessarily stimulated by components that should remain in the intestine, such as harmful bacteria. In practice, you often see that everything is connected in horses with sensitive intestines: manure stability, abdominal comfort, stress reactivity, and skin/coat condition. It is not a one-to-one relationship, but it is a pattern that should be taken seriously in preventive care.
The largest part of the immune system, up to 80%, is in contact with the intestine. Most of what enters the body daily comes through the intestine, such as fiber, sugars, bacterial fragments, and stress signals via the nervous system. SCFAs are described in immunological literature as important for protecting the intestinal barrier and regulating immune responses.
For horses prone to eczema, this does not translate to "this prevents itching," but rather to: a well-functioning intestinal environment can contribute to a body that is less likely to become overstimulated when external stress increases.
In spring, there are often several changes at once: insect pressure, grazing, sometimes different rations, and more training. For a sensitive horse, this accumulation of changes can upset the balance. A preventive approach therefore works best when you start well before this accumulation of changes, so that the system is already running more smoothly when the season changes.
This protocol is deliberately practical and action-oriented. Think of it as a roadmap.
Phase 1 (weeks 0–2): stabilize the foundation
You start with predictability. The microbiome likes regularity, and it is precisely in horses prone to eczema that you often see fluctuations in roughage, feeding times, concentrated feed, or stress translating into fluctuations in manure and comfort.
In this phase, you make the ration as consistent as possible: good roughage is key. We introduce any changes slowly and take a critical look at fast carbohydrates that can challenge the hindgut. At the same time, you take a baseline measurement. Not with a spreadsheet, but with simple observations: how stable is the manure, how often do you see manure water, how does your horse's belly feel (also around stress or training), and what is the general skin and coat quality like?
Phase 2 (weeks 2–10): targeted support with Happy Belly Solid (calcium butyrate)
When the base is calmer, add targeted support. Happy Belly Solid is a prebiotic based on calcium butyrate: a compound of butyric acid (butyrate) and calcium. Butyric acid is a short-chain fatty acid and is known as a source of energy for intestinal cells and for supporting normal intestinal function; in the literature, butyrate is also linked to barrier function and immune modulation.
In practice, this route is often suitable for horses with variable manure or manure water, horses that are sensitive to feed or stress, horses with a history of antibiotics, and horses that are prone to eczema and want to build up preventively towards spring. Support for intestinal function and digestion can also be appropriate for older horses, especially during periods when the body undergoes significant changes (such as shedding).
It is important at this stage to keep your results measurable. Choose one or two fixed indicators that you can reliably monitor, such as manure stability and abdominal comfort. Skin and coat condition can be used as supporting indicators, but don't expect spectacular "before and after" results in winter.
Happy Belly Solid works so effectively in practice precisely because the calcium butyrate is coated. This coating is not a minor detail, but essential: without protection, some of the butyric acid would be released early in the gastrointestinal tract and be less effective in the place where you ultimately want it to be. The protective layer allows the product to better withstand passage through the stomach and become available in the (large) intestine, where butyrate is intended to nourish the intestinal cells and support the intestinal wall ("barrier"). You can even see this coating in the product: it consists of recognizable small granules/beads. This means that you are not just supplying "something for the intestine," but an active substance that is designed to play its supportive role in the right place.
Phase 3 (weeks 6–10): evaluation and fine-tuning
If you see little change, don't immediately start adding more supplements. First, systematically check whether the basics are really right: roughage quality, (hidden) starch load, chewing function/teeth, worm pressure, and sources of stress. If the manure remains abnormal or there are clear signs of pain, it is wise to consider diagnostics via your veterinarian instead of endlessly adjusting at the supplement level.
To keep this protocol workable, these are the three observations that provide the most guidance in practice:
A healthy microbiome produces SCFAs, and butyrate is a key substance in this because it nourishes intestinal cells, supports the barrier function, and can help regulate immune pathways. For horses prone to eczema, it makes sense to start building up in winter or early spring: you work preventively at the basis, before the external stimuli of the season increase.
Would you like us to help you determine which step is best suited to your horse and your feed ration? Feel free to contact us for personal advice.
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