The use of garlic is widespread among horse owners, and its medicinal use in humans has been documented as far back as Ancient Egypt for the treatment of heart disease, tumours, worms, bites and other ailments. The Greeks and Romans used large quantities for treating and preventing various ailments, and to give stamina and strength.
Today, garlic is well recognised for its ability to help with heart disease, but it is also effective in the treatment of fungal, bacterial and viral infections. Garlic must be one of the most studied herbs, but it is so much more than a medicinal one.
Multiple use
Garlic has both anti-fungal and anti-bacterial properties. Against fungi, it seems, it can act just as effectively and more quickly than chemical anti-fungal agents.
An Adelaide doctor described in The Medical Journal of Australia how his family were all infected with ringworm from a stray kitten. His teenage daughter, the last to suffer, decided to try garlic. She treated one arm with it, and the other with the modern chemical drug other family members had used; the lesions on her garlic-treated arm healed in 10 days, while the other took nearly four weeks.
Several case studies have demonstrated garlic’s antibacterial activity on humans. In the most striking, groups of burn victims with less than 45% of total body area were compared. Those receiving just two cloves a day developed significantly fewer burn wound infections than the non-garlic group.
It’s also been shown in lab experiments that fresh garlic is at least as effective as any of the common antibiotics in dealing with a very wide range of bacteria, including those causing food poisoning, digestive problems, throat, lung and skin infections. The most effective of the antibiotics tested was chloramphenicol, which worked better than penicillin, tetracycline, streptomycin and others. Yet garlic matched chloramphenicol and, in two cases, killed bacteria resistant to it.
Personal experience bears this out. Years ago we had a calf with joint ill. It had had repeated courses of antibiotics with no lasting effect and the infected knee had erupted. We fed the calf fresh garlic and packed the open joint with fresh cloves. Sure enough, the garlic did what the antibiotics could not, and the calf recovered and thrived with only a chronically swollen and slightly stiff knee.
Garlic is traditionally used to help repel parasites, although studies are hard to find. We did a trial some years ago on goats and garlic indeed lived up to its reputation in this area. We have also found that continued use of garlic is an effective control against parasite build-up.
Garlic is also a tonic to the respiratory system and helps prevent coughs and colds.
Fresh is best
The trials reported above used fresh garlic. There is no doubt that fresh is best and if you are using garlic to treat an infection of some kind it is well worth the effort.
However, if you are feeding a lot of horses, the use of fresh garlic can be quite demanding. Fortunately, it is available in a number of other forms. Most readily available are probably garlic powder and granules. We don’t think there is much to choose between them but have always used powder; it tends to be cheaper than granules. Be careful, though, as it attracts water and gets very sticky. Keep it well sealed in a plastic bag.
Can I give too much?
Yes. Over the last few years there has been quite a lot of media comment, which has painted garlic in a bad light. The issue is Heinz body anaemia. High levels of garlic cause the haemoglobin in the cell to oxidize and form a ‘bubble’ – called a Heinz body – on the outside of the cell. It’s quite distinctive and readily seen under a microscope. The spleen quickly removes the deformed cell from the bloodstream.
Then, as more and more red cells are prematurely damaged and removed, as will happen from continuing excessive garlic in the diet, your horse gradually becomes anaemic. Once the garlic is withdrawn the horse should recover.
Garlic is a popular supplement and generally considered safe in normal use. In tests, a daily dose of more than 0.2 grams per kilogram of body weight was needed to cause Heinz body anaemia. This is equivalent to 100gm of garlic powder for a 500kg horse. A more normal dose of 20 to 30 gm should be fine.
Recommendations on how much to give vary depending on your source, but we have found that about a dessertspoonful of powder (20-30gm) or half a fresh head is a good daily dose for an average sized horse. If you are treating an infection, increase the dose to at least twice and try to use fresh garlic. As a reference, an average head of garlic weighs about 50g.
Garlic chemistry
Don’t be put off by the c-word; the concept is easy (but the names are a bit of a mouthful). One of the main active ingredients in garlic is a chemical called allicin. Allicin is what gives garlic its wonderful smell when you crush it. It is also the most important active to get into the body – what you smell is wasted.
Allicin is released when its precursor, alliin, is acted on by an enzyme. This happens when the cells are ruptured and there is water or oxygen present, as in the fresh bulbs or when powder or granules are exposed to the air. Powder and granules are stable until they are ingested or have water added. Try it and notice the change. It is therefore better to feed garlic powder or granules dry, because the allicin is quite unstable once formed, and within a fairly short time will degrade to less effective compounds.
