As the saying goes, "Beauty comes from within," and the skin is a direct reflection of what’s happening beneath the surface. When it comes to itchy skin, the root cause often starts with the gut.

Sweet Itch: More Than a Skin Problem

Sweet itch, one of the worst equine skin torments, has been a personal battle for two of Carol's (EquiNatural's founder) horses, Kelso and Mac. While it was traditionally thought to be an autoimmune response to the Culicoides midge, recent research (2021) reveals that sweet itch is not merely a skin issue. The skin symptoms are undeniable, but the underlying cause lies in the gut, where a significantly disturbed microbiome leads to extensive inflammation of the gut lining.

This inflammation triggers a hyperactive immune response, leaving the body highly sensitive to allergens and resulting in a massive increase in toxins. In essence, sweet itch is an autoimmune issue.

The Role of the Kidneys and Skin

The kidneys, tasked with excreting toxins while maintaining vital balances (acid-base, minerals, water, and blood pressure), have a limited capacity. When overwhelmed, the y rely on an emergency detox pathway—the skin. This overload leads to excessive toxin excretion through the skin, causing severe itching, particularly in summer when insect bites compound the problem.

Fly rugs can help by preventing midge bites, reducing symptoms. However, for some horses, the metabolic burden is so overwhelming that the skin becomes the primary elimination organ. This explains why some horses scratch persistently, even in winter.

The Hidden Danger of Kidney Overload

A major challenge is that kidney insufficiency often remains invisible until significant damage - up to 70% - has occurred. This makes early intervention critical. For sweet itch or fly-affected horses, fly rugs provide some relief, but for horses with non-sweet itch-related skin issues, the root cause is often severe gut biome dysbiosis.

A Whole-Body Approach

To truly address itchy skin, we need to consider the entire detoxification system: the gut, liver, and kidneys. If the kidneys are overloaded, the liver is likely struggling too, disrupting the toxin biotransformation process. This creates a chain reaction that begins with gut biome imbalance and ends with the skin serving as an emergency excretion pathway.

This same process applies to conditions like mallenders and sallenders, which are also linked to impaired liver and kidney function.

What to do Next

1. Stabilise the Skin Biome: avoid harmful, chemical-laden shampoos that strip the skin of its natural oils.
2. Fortify the Diet: Replace ultra-processed feeds with clean, grass-forage-based feeds (e.g., grass nuts, cobs, or chaff). Keep sugar and acid content low. If your horse has been fed haylage, feed spirulina for one month to bind intestinal toxins, deacidify the hindgut, and support gut health. Provide ad-lib stemmy hay to ensure plenty of cellulose fibre is passing through the colon, helping recolonize beneficial hindgut microbes.
3. Additionally, linseed has been shown to help control itchy skin caused by Culicoides midge bites (Canadian Journal of Veterinary Research, October 2002).

New Research

As of October 2021, emerging research suggests that sweet itch is connected to a widespread, multi-metabolic detoxification disorder called Cryptopyrroluria(KPU). For more information, visit our KPU page .

For the latest research and updates, see our main A-Z Coat & Skin page.

Dried Herbs

Human grade, produced to ecological standards and free from agro-chemicals. See our Quality page for Organic Certification Documents.

• Feed 5g/100kg bodyweight per day, i.e. 25g for a 500kg horse.

Tincture

• Feed 6ml/100kg bodyweight per day, i.e. 30ml for a 500kg horse. Shake well before use.

I am pleased to report that Persia, my sweetitch mare is much much less itchy (and there have been plenty of midges about), she has finished the detox so is now just on the SwItch. Nothing else has really helped so I am delighted! Imogen P.

I'm so impressed with the SwItchTonic and how is working for my sweetitch lad. Best regards, Nicola (from France)

I just wanted to let you know that I have been feeding the SwItchTonic herbs and his skin has improved and (I dont want to speak too soon but) his sweetitch has been the best it has ever been this year! So thank you so much! He is also doing very well at competing and people cannot believe how old he is, when I get a new photo I will send it through to you. Liane and horses

The herbs have turned out to be something of a miracle for Fern. She stopped itching within a couple of days and is definitely more relaxed. She still has quite a bit left so (due to Christmas cash flow)I will be ordering some more in the New Year. Thanks again for all your advice and your excellent products.