Are you planning to feed garlic to your horse? Here are 7 things to know beforehand.

Dewormer, insect repellent, antioxidant... The virtues of garlic seem endless. Its properties have been praised for decades: integrated in food supplements, alone in flakes or in powder, garlic can be declined over and over again and promises to improve the life of your horse!

However, although natural, garlic is not without its sometimes serious side effects when used incorrectly or for too long. If you're planning to give garlic to your horse, here are seven things you should definitely know before you do!

1. In what form should you give your horse garlic?

Garlic is often offered in multiple forms:

• It can be bought dehydrated: in flakes, pellets, powder...
• Or fresh: whole in cloves, crushed, just peeled.

Most of the time, it's mostly a matter of taste (for the horse) or convenience (for the groom).

Besides, no matter what form it takes, garlic is granted the rank of miracle cure for all sorts of horse ailments: worms, insect attacks, small boo-boos, respiratory discomfort, impaired blood circulation, and even sometimes, we read that it can act against cancers.

So, fact or fiction? Animaderm offers you a small tour of the proven benefits and received ideas concerning this so familiar seasoning.

2. Is garlic safe for the horse?

Garlic is natural, it can't hurt my horse. FALSE!

We'll stop you right there! Just because a product is natural does not mean it is safe. As the old saying goes: it's the dose that makes the poison.

Whether you use a natural product or not, the question is always to define the dosage. And this dosage varies not only according to the plant, the nature of the active principles, the species that one intends to treat but also according to the form in which it is chosen (fresh plant, essential oil, dry extract, purified extract, macerate...)

How can garlic present a danger to the horse?

As you will have realised, garlic obeys the same rules as other plants with powerful active ingredients. Due to its high concentration of sulphur compounds, garlic ingested in too large quantities or over a too long period of time can thus cause:

• damage to the digestive tract: if doses of garlic (whether fresh garlic, garlic flakes, garlic meal or garlic powder) are high and especially regular, they can cause damage to the digestive mucosa of the horse and even lead to bleeding ulcers as well as a decrease in nutrient assimilation.
• Diarrhoea
• clotting problems: some research tends to prove that sulphur compounds in garlic inhibit platelet aggregation and prolong bleeding times.
• anemia: the disulfides in garlic (and onion) promote the oxidation of hemoglobin within red blood cells, leading to increased hemolysis (a destruction of red blood cells).

Focus on: anaemia in horses and garlic

Anemia caused by garlic is a well-known and documented phenomenon in dogs. It has also been demonstrated in the horse. The studies conducted to understand the action of garlic on horses have, among other things, raised the dosage issues we were just discussing.

We have very briefly summarised two study reports to give you a better understanding of the implications of garlic in anaemia in horses:

• Garlic effects in the horse: a clinical report by E. Valle et al; 2006. A presence of anaemia was detected after administration of high doses of garlic in the ration (100 grams of dehydrated garlic per day) over a short period (10 days)
• Influence of garlic supplementation on respiratory health and incidence of anaemia in horses by M. Saastamoinen et al; 2010. A presence of anaemia was detected after administration of garlic doses in the ration lower than the amount generally recommended and therefore considered low (16 grams of garlic powder per day) over a long period (83 days).

In the case of rapid ingestion above the recommended doses, anaemia may be detected quickly. But under conditions of long-term ingestion of small doses, anaemia may set in gradually and insidiously, affecting the general health of the horse without obvious symptoms.

When is it not advisable to give garlic to horses?

The garlic is contraindicated for horses with blood clotting problems or anaemia. In any case, we advise you never to give garlic in too large quantities or as a prolonged course of treatment (for more than a month). Also beware of interactions with medical treatments.

At the same time, we recommend that you do not give garlic in large quantities or as a prolonged treatment (for more than a month).

Besides, speaking of medications...

3. Did you know that garlic is a powerful antibiotic?

Uses of garlic as an external antibacterial:

The antibacterial properties of garlic have been known since ancient times. Louis Pasteur demonstrated its antibacterial properties in 1858. On the battlefields, garlic was even used directly on wounds as an antiseptic during the First and Second World Wars, during which it was dubbed "the Russian penicillin". This property comes from allicin, an organosulfur compound abundant in garlic and its derivatives.

Allicin is a potent broad-spectrum antibacterial, active on various strains of streptococci, staphylococci, enterococci, salmonella and shigella, but also an effective antifungal on aspergillus or candida sponges for example.

But beware: the use of garlic as a skin antibiotic requires increased knowledge of its properties. The risks of burning or allergic reaction if applied to the skin are high.

The use of garlic as a skin antibiotic requires greater knowledge of its properties.

Can garlic be used to fight bacterial infections internally?

Few clinical studies have looked at this question, making the answer difficult. What is known is that allicin is a very unstable compound and is unlikely to exert its antibiotic action in the body.

The reason for this is that garlic is a very effective antibiotic.

In fact, once ingested, allicin will quickly break down into about 100 other sulphur compounds, such as allyl disulphide, diallyl disulphide or even ajoene, in varying proportions, making it very difficult to detect in the blood.

4. Does garlic provide interesting vitamins and minerals to horses?

Yes and no. Although compared to other foods, garlic is quite rich in:

• B-group vitamins and vitamin C
• minerals (selenium and iron)
• oligo-elements (calcium and phosphorus)

As a dietary supplement in the horse's ration, its intake remains negligible, particularly because of the amount consumed, which is usually only a few grams. On average, a clove of garlic weighs less than 5 grams.

5. There is no evidence that garlic scares away insects

It all depends on how it is prepared and used: fresh, dried, decocted, oil, ingested or applied directly to the skin; the dose; and the species of insects targeted.

Garlic repels... vampires?

When applied to the skin, garlic has a reputation for being an effective insect repellent against most insects including haematophagous insects: those that feed on blood and bite our horses to the point of insanity such as louse flies and simuliums (midges). Unfortunately, it is very volatile and unstable: its active principles degrade quickly.

Therefore, the insect repellent action of garlic is only short-lived.

Caution: prolonged use of garlic preparations and pure garlic may cause irritation or burns, or even allergic reactions!

Will garlic in the horses' ration keep flies away?

The ingestion of garlic remains highly controversial with regard to its effectiveness in repelling insects. Few scientific studies have looked at the insect repellent efficacy of ingested garlic, either in humans or animals. Generally speaking, the results are inconclusive...

The only way to get an idea is through user testimonials. And to tell the truth, the results are quite disparate. Some see a difference, others not at all. On the other hand, and as mentioned above, be extremely cautious about the side effects that can be associated with regular garlic consumption, even at low doses (anaemia, digestive disorders and blood clotting disorders).

6. Can you deworm horses with garlic?

Here again, it is difficult to answer. Although garlic has been used for centuries to deworm humans and livestock, this use would be based more on tradition than on scientific grounds.

Positive results have been obtained in vitro on several species of internal parasites but the few publications listed provide rather discordant results when the experiments were transposed in vivo. On the other hand, the heterogeneity of the protocols used (duration, dosage, mode of preparation of garlic) makes the analysis very complicated.

To come back to the testimonies and opinions of users, as in the case of garlic as an insect repellent, in the case of garlic as a dewormer: difficult to rule.

Infestations before and after treatment are difficult to assess without coprological and blood tests. Yet, if some ask for a coproscopy after treatment, few ask for them before, in order to establish a comparison...

7. What type of garlic to choose for my horse

Fresh, crushed, dried, boiled... are all forms of garlic the same?

No, they aren't. The content and nature of the active ingredients in garlic will depend on a large number of factors, and will therefore be influenced by the methods of preparation and/or extraction. The main forms of garlic administered to horses are:

• raw garlic, raw or crushed,
• dried garlic, in powder, meal or flakes,
• garlic pellets.

But you can also find on the market:

• garlic essential oil
• garlic vegetable oil
• or aged garlic extracts (AGE)

What are the scientific differences between the forms of garlic?

The intact garlic clove: systems for the appearance of allicin

In the intact clove, allicin is absent. Only when fresh garlic is crushed or minced does the enzyme alliinase convert alliin to allicin. It is allicin that is responsible for the aroma of fresh garlic. In nature, allicin is garlic's main defence against herbivores, parasites and insect pests: it is a potent anti-parasitic and an irritant.

At room temperature, allicin begins to appear quickly after being "assaulted" (bitten, chopped, crushed...) but it takes about fifteen minutes for much of the alliin to be converted to allicin.

Processed garlic clove: lack of allicin

The alliinase, is very sensitive to temperature and pH. Therefore, cooking, as well as too acidic a pH (pH above 3) definitely inhibits the enzyme.

The chemical reaction that converts alliin to allicin cannot therefore take place once the garlic reaches the stomach or intestines (because the pH is too acidic), or when cooking the just-crushed cloves (because the temperature is too high).

Dried garlic powder would not contain allicin either, but it does contain alliin.

Feeding a whole clove or cooked or dried garlic as is would therefore not be the best way to get the benefits to your horse. One of the best methods would be to add water to the dried garlic and wait a few minutes before giving it to your horse, which would allow the allicin to form, but again, this is all very theoretical.

Are you looking for a natural alternative to keep bugs off your horse?

Everything that can improve the well-being of horses concerns us. That's why we study new scientific publications, latest veterinary opinions, as well as the latest discoveries in dermatology and cosmetology for horses everyday.

It is in this effort to act daily for the well-being of our horses that we have created several 100% natural products that will effectively protect them from flies, midges, ticks and other insects:

• Derfly™: the biomechanical 72H fly repellent
• Natjely™: the vegetable Vaseline that prevents ticks and louse flies from sticking to the coat
• Shampoo Tea Trea™: the soothing shampoo with Tea Tree enriched to calm bite-related irritations

Information for guidance only - Not a substitute for a vet consultation