Natural Horse Wormer: Verm-x

There are many more “pro’s than “cons” for using a natural horse wormer, provided that the worm burden is monitored and field are well managed – regular poo picking

Natural Horse Wormer Pro’s & Con’s

Horse worms are becoming increasingly resistant to chemicals, as companies encourage us to overuse horse wormer in pursuit of profit.

With regular poo-picking, natural wormers can be a real alternative to chemicals.

Alternatively, they can operate in tandem with a chemical wormer. For example, some owners will use a chemical wormer annually for encysted redworms, but throughout the year use a natural wormer.

Monitoring the worm burden is still essential – click here to find out how

Below are some overall pro’s and con’s of “natural wormers” with specific reference to internet research conducted on the Verm-x product.

Gentle on horses stomachPossibly not so good for dealing with severe infestations that require a “big hit”.
Easy to administer – horses like it and therefore do not “spit” or resist a syringeRequires diligent pasture management (poo picking) to be effective
Suitable for pregnant animals
Risk of overdose or contamination very small – contains natural ingredients
No adverse reaction, such as weight loss or hoof rings
Suitable for horses allergic to other wormer
Can be cheaper that chemical wormers
Better for the environment and does not perpetuate chemical resistance

Not  really a “Con”, but readers should note that because this is a natural product it does not require a pharmaceutical license and therefore cannot be described as a horse wormer in any advertising literature

Horse worms are becoming increasingly resistant to chemicals

Parasitic resistance to wormers, resulting from the overuse of chemical horse wormers,  is becoming a growing problem.

Horse owners have been encouraged by the big pharmaceutical companies to regularly dose horses every 6 to 8 weeks all year round. This approach ignores any impact of good pasture management, climate, and worm biology & life cycles.

Increasing resistance in redworm populations, particularly the small redworms (Strongyles) to wormers of the Benzimadole group, has been confirmed by the Moredun Research Institute.

Pinworms (Oxyuris equi) are also a growing problem. UK livery yards report many horses are carrying heavy burdens of pinworms immune to conventional wormers.

Routinely deworming with chemicals kills all worms susceptible to chemical & bacterial wormers. However, this leaves the resistant worms to lay eggs and multiply unchecked.

By concentrating high doses of chemicals on worms resident in the horse, a gene pool of super-resistant worms has evolved that are resistant to both chemical and bacterial wormers.

After each deworming cycle, their resistance increases, ultimately leading to your pasture infected by a strain of super worms resistant to chemicals.

A super-worm infected pasture has severe health implications for horses with conditions such as anaemia, gut ulceration, colic etc.

Should I Use a Natural or Chemical Horse Wormer?

The consequence of this overselling and overdosing has been the development of super-resistant horse worms. The simple truth is that horses do not need to be dosed all year round every 6 to 8 weeks to be worm free.

Rotational Deworming With Chemicals

In recent years, rotational deworming (by using drugs of different classes for each deworming) has been promoted as a method to overcome resistance.

In America and Northern Europe, resistance to two of the three dewormer drug classes – Benzimidazoles (i.e. Fenbenzadole and Oxibendazole) and Pyrimidines (i.e. Pyrantel) is increasing.

There have also been reports of resistance to macrocyclic lactones (Ivermectin, Moxidectin) in Europe and Brazil.

No longer can we rely on rotational worming to kill all horse worms. Alarmingly, these three classes of chemical dewormers are the only parasite killing drugs (anthelmintics), the pharmaceutical companies have to offer.

A New, Natural Approach to Effective Worm Control

Responsible horse owners worm their horse, seasonally and, on well-managed pasture, significant worm burdens are not a problem.

Given the increasing immunity to chemicals, it is critical to not only worm your horse but to follow deworming with a faecal egg worm count, in spring and winter. An ELISA blood test, done in autumn following deworming will determine the presence of tapeworm.

Faecal egg worm counts are vital to determine worm burden but do not indicate the presence of tapeworms.

To check the level of tapeworm infestation in your horse, you will need to ask your veterinary surgeon to do an ELISA blood test to measures the level of antibody to a specific tapeworm antigen.

Focus on Big Worm Picture

Future measures to control the parasite burden on pasture will need to focus on the bigger picture, the factors outside the horse that influence horse worm populations

Worm Biology

Breaking the continuous life cycle by removing faeces, you destroy eggs waiting to hatch, effectively reducing the numbers of L3 infective larvae ingested by your horse. Yes, pooh picking weekly at a minimum (we poo pick daily).

Climate & Temperature

Using climate & temperature to determine whether your horse may need deworming. The life cycle of horse worms, the climate requirements and conditions for successful hatching and survival will determine your worming schedule. See the article “Establishing a Worming Programme”


Deworm for redworm larvae as soon as night temperatures dip under 10°C and before ground frost becomes a reality. Expel them before they start to encyst and overwinter. Don’t bother to do a Faecal Egg Count, because immature larvae don’t lay eggs.

Introducing Horses to the Herd

Isolate all new horses until dewormed, and FEC count results clear them. Care must be taken not to introduce horses from yards with known resistant worm strains.

Responsible Pasture Management

The removal of faeces, harrowing in hot weather and rotation of grazing, all help to break the red worm life cycle.

Improving Forage

Seeding pasture with tannin-rich forage such as sainfoin, birdsfoot trefoil, yarrow, chamomile, wild marjoram. Don’t grub out old hedges full of natural dewormers such as bramble tips, rose hips, crab apples and elder shoots. Horses will instinctively pick out the shoots.

Herbal Horse Wormer

Consider using traditional herbal wormers to stop the build-up of resistant worm strains, usually referred to as “Internal Parasite Repellents”.

Herbal products can be useful if your horse will not accept the syringe based delivery straight into the mouth,  required by a number of chemical products. They can also be good if your horse has sensitive digestion.

Vary the type of wormer used, alternating chemical wormers (that you have proven effective after monitoring worm counts) with herbal parasite repellent products such as Verm-x.

Carefully document all worm test results. Successive high FEC’s, indicate a resident population of super-resistant worms.

Natural Worming Product – Verm-X

Verm-X is a natural horse wormer that has been on the market now for over 15 years. It has been formulated because of the resistance concerns raised in this article. In the video below, Dr Sarah Beynon talks about the overuse of pharmaceutical wormers and their impact on the natural environment, including killing off the dung beetle population.

  • Contains natural ingredients: Garlic, Cinnamon, Common Thyme, Peppermint, Fennel, Cleavers, Nettle, Slippery Elm, Quassia, Elecampane
  • It works over a 21 days cycle, rather than an immediate purge, as with chemical products. This is more gentle on the horse’s stomach
  • Can be mixed into food and water, so administering this has a minimal impact – especially if you have a stressy horse

Interestingly, the company reports no instances of resistance to Verm-X.

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