Worm control is one of the most discussed topics in equine care. While conventional deworming medications remain essential in many situations, an increasing number of horse owners are exploring natural approaches to maintaining a healthy intestinal environment. Botanicals have been used for centuries to support normal gut wellbeing alongside an appropriate, vet-led worming programme.
This guide examines the herbs most commonly associated with natural worming support, explains how they work, and outlines safe, practical ways to incorporate them into your horse's routine. It is not a substitute for veterinary advice or faecal egg counts — rather, a resource for those seeking to complement conventional care with time-honoured botanical wisdom.
Understanding Equine Parasites
Horses are exposed to a range of internal parasites throughout their lives. The most common include large and small strongyles, roundworms (ascarids), tapeworms, and pinworms. These organisms live in the intestinal tract, competing for nutrients and, in heavy burdens, causing weight loss, colic, diarrhoea, and poor coat condition.
Resistance to conventional dewormers is a growing concern worldwide. Frequent chemical dosing has led to populations of parasites that survive treatment, making strategic, targeted worming — guided by faecal egg counts — the modern standard. Botanicals may be fed for normal gut wellbeing but cannot control parasite burdens; testing and veterinary guidance remain essential.
Key Botanicals for Worming Support
Wormwood
Artemisia absinthium
Traditionally included in botanical gut-support routines.
Wormwood has a long history in herbal tradition as a bitter gut herb. Its bitter compounds, including absinthin, are traditionally associated with supporting a gut environment less hospitable to imbalance. It should be used short-term and in carefully measured amounts, as excessive quantities can be toxic. Wormwood is not a wormer and does not replace faecal egg counts or a vet-led worming plan. Always source dried, equine-grade wormwood from a reputable supplier.
Garlic
Allium sativum
Traditionally fed to support normal gut wellbeing.
Garlic is a traditional ingredient in equine botanical feeds. Some owners include moderate amounts as part of a normal gut-support routine; it does not deter parasites or replace a vet-led worming programme.
Pumpkin Seeds
Cucurbita pepo
Nutritious seeds traditionally included in gut-support routines.
Pumpkin seeds have a history of use in traditional gut-support feeding. They supply nutrients but are not proven to remove or control parasites in horses; keep to your vet-led testing and worming plan.
Clove
Syzygium aromaticum
Traditionally included in herbal worming blends to support a healthy gut environment.
Clove bud oil is rich in eugenol, an aromatic compound traditionally associated with herbal worming routines. In herbal worming routines, clove has traditionally been included as part of a balanced blend. Whole or ground clove should be used sparingly and as part of a balanced blend rather than in isolation.
Thyme
Thymus vulgaris
Traditionally used to support a healthy gut environment with naturally aromatic essential oils.
Thyme contains aromatic plant compounds and has traditionally been included in botanical feeding routines for normal gut comfort. It does not replace parasite testing or licensed wormers.
Diatomaceous Earth
Fossilised marine algae
A silica-containing material, not a proven wormer.
Diatomaceous earth is a powder made from fossilised microscopic organisms. It has not been established as an effective parasite treatment in horses. Ask your vet before adding it to feed and never use it in place of testing or licensed wormers.
Feeding Guidance
Natural worming support works best as part of a broader intestinal health strategy. Botanicals are not a direct replacement for veterinary dewormers, but they can complement a well-managed parasite control programme.
- Use faecal egg counts: Know your horse's parasite burden before deciding on any worming approach.
- Rotate herbs seasonally: Avoid building tolerance by varying the botanicals you use throughout the year.
- Feed in cycles: Many owners follow a 6–8 week on, 2–4 week off pattern for herbal worming blends.
- Buy equine-grade products: Human supplements may contain additives unsafe for horses.
- Consult your vet: Discuss herbal protocols alongside conventional worming schedules.
When to Call the Vet
Natural support is valuable, but certain signs demand prompt veterinary attention. Do not rely on herbs alone if your horse shows any of the following:
- Severe or sudden weight loss
- Persistent diarrhoea or colic
- Dull coat, poor appetite, or lethargy
- Visible worms in droppings
- High faecal egg count (ask your vet for thresholds)