Herbs for Health





Herbs, the buzzword on biters!

By Lynn Carrick


Myrtle bushes, Shackleford Banks, NC. The mustangs rub themselves against it. The oil from the leaves helps repel deer ticks and flies and gives their coats a beautiful shine. Photo courtesy of Elizabeth Loftin

Ah... late spring. It's perfect weather for riding. Not too hot yet, not too muddy. Flowers are blooming everywhere and all the little critters who slept away the winter are back, happily tending to their little critter businesses. Unfortunately, so are the even tinier critters that don't cause fond emotions to well up in our hearts when we first notice them. Yep. Insects.

Bugs, those little biting, stinging, irritating harbingers of summer. While we're glad to have summer on its way, it sure would be nicer not to have the little pests annoying us directly. Sure, we know they're a necessary part of the ecosystem, but hey, little guys, how about doing your part for Mother Nature somewhere else?

Majestead in the myrtle bushes. "He'll rub against these until he shines like copper and his mane looks like someone brushed it for him," says Elizabeth. Photo courtesy of Elizabeth Loftin

Insects can be annoying pests, and may also pose a serious health threat to animals and humans, especially when their immune defenses are down. In some cases, the substances used to repel them may be causing serious health threats of their own.

One substance that has been widely used in products designed to repel insects (for human use) is particularly controversial. Diethyl toluamide (DEET) has been tested and approved as a bug repellent and is added to many products on the markets in various percentages. However, this chemical is suspected of causing such health problems as restlessness, abnormally rapid breathing, headaches, crying spells (particularly in children), staggering, convulsions and possibly even coma. Children may be particularly susceptible to its effects. DEET levels of 15% or less should be weak enough to avoid side effects. People who have skin conditions should be very careful with products containing any percentage of this substance. Accidental ingestion (swallowing) of DEET in any product is very dangerous, and should be treated as poisoning. Contact the poison control center and/or the emergency room of a hospital immediately. Furthermore, DEET can melt plastic when sprayed on or applied.

Repelling insects such as mosquitoes and ticks that can carry Equine Infectious Anemia (what we do the Coggins test for), Lyme disease, Rocky Mountain Spotted Fever, encephalitis, among others, or even just cause painful or itchy bites is an important issue. To protect ourselves and our animals from these potentially serious medical problems, there are other options that can be considered which don't involve the use of DEET. Many plants and vitamins contain substances which tend to repel insects, and do it safely.

One of the substances in flowers and other plants found to be the most effective in repelling insects is called "coumarin". Coumarin is common in many plants, such as Ageratum, which is a common garden flower. There are some other, more toxic substances in Ageratum and some other flowers, which would make them unsuitable for rubbing on the skin, but the coumarin itself is very effective. It is found in Avon's Skin-So-Soft, which, though not marketed as an insect repellent, happens to be very effective at doing just that. Coumarin can also be obtained at science supply stores. It is described as smelling like "new-mown hay" and is used commercially in many perfumes. However, it is NOT to be taken internally, as it may cause liver damage.

Wild Geranium


The natural oils of certain plants and flowers, when rubbed on the skin, hair coat or fur, can also repel insects. Basil is effective in this way and when grown in huge patches, will sometimes attract cats and dogs that will roll in it to get the benefit of its strong scent. Lemon balm, a perennial that can grow as profusely as any mint, is another herb which can be used this way. Wild Geranium, used as a base for shampoo, is superb in the treatment of lice, scurfy or scaly skin, and also repels mosquitoes. Pennyroyal and frankincense are two other effective fly repellent plants.


Rosemary's essential oil smells a bit like camphor (though thankfully, the herb itself doesn't!) and its own properties include a very effective insect repellent. The fragrant leaves can be crushed into a fine powder, dusted into the hair coat of horses, sprinkled onto the fur of dogs and cats, or even added to their bedding. They can also be broken down less finely, into a sort of tea-like texture, and soaked a while in warm water. Used as a rinse or spray on horses, dogs, and cats, rosemary will repel fleas and other biting insects. Added to feed, it helps do the same thing.

Citronella, from the plant of the same name, has been used to make soaps, candles and other items, and has been considered of some value as an insect repellent, though it is weaker than coumarin or DEET, and it doesn't work on ticks or chiggers. It will repel mosquitoes and some fly species.

There have been studies of yarrow as well, showing that it contained several compounds which have excellent insect repelling properties. A decoction of yarrow in some sort of cream such as lanolin might be the longest lasting sort of repellent. Yarrow is suggested for wound dressings in horses, and its insect repellent properties make it particularly beneficial. While it helps to heal the wound, it will keep the busy biters away. Yarrow can also be infused in other liquids suitable for application on skin, hair coat or fur.



Some plants, such as rosemary and basil (when they are planted in large quantities), can actually benefit a larger area by being planted in spots where sun and wind will release their natural scents into the area. Rue, for example, is a perennial bush that will keep ants away, because of its strong, bitter scent. Single-leaf Tansy is another tough perennial that can be grown easily. Its rich green leaves and fern-like appearance, along with its bright yellow button flowers, make it a good choice for borders and hedges and its pungent leaves are a very effective insect repellent. Southernwood (Artemisia abrotanum) is another strongly aromatic, shrubby perennial with insect repelling properties, both by being planted in an area and when rubbed on the skin. Horses have been known to rub against it when it is hung in their stalls. It is particularly effective against flies and moths. The fragrant leaves of Sweet Gale (Myrica gale, also known as Bog myrtle, is an aromatic deciduous shrub with resinous nuts) also repel insects and moths.

According to Elizabeth Loftin, expert on the wild ponies of Shackleford Banks, NC (in correspondence with our Editor), "Myrtle bushes are great substitutes for fly sprays and they repel fleas and ticks. You can hang the branches in stalls for the horses to naturally rub against or shuck the leaves off the branches, like shucking corn, and mix the leaves in with the regular bedding whether it's shavings, straw, or just a dirt floor. I actually rub the leaves on my horses. I scrub it into their coats like a massage and then finish with a normal grooming brush. This method not only eliminates flies, but leaves the coat shining like you won't believe! The wild mustangs of Shackleford Banks taught me this one. They groom themselves naturally in the myrtle bush groves on the island."


Some herbs and vitamins can help repel insects when eaten. Eating garlic has long been known to affect not only the smell of a person's breath, but also the smell of their perspiration because of the spread of its oils throughout the bloodstream. Even if the smell is very faint or even imperceptible, it can be enough to repel insects. Other plants have the same properties. Peppermint can repel ticks when the fresh leaves are eaten and horses, in particular, will eat it readily. Garlic is also a natural insect repellent, in addition to its therapeutic value with regard to both circulation and digestion. Used internally, it also helps with mange. Garlic flower essence can be useful in preventing fleas and ticks on dogs, cats, and horses. Thiamine, also known as Vitamin B-1, is thought to repel fleas when it is present in high levels in the blood of dogs and cats.

Yes, our little critter friends are out there in force, ready to take a bite out of us, and our equine, canine and feline friends. But they don't have to be pests to any of us. Be prepared for them. Now would be a great time to run out to the nursery and check out some plants you can grow and use for insect repellents. Enjoy their beauty, their scents, and all their natural benefits. And while you're at it, have a great, insect-free, summer!

As always, consult your veterinarian, physician, and qualified herbal expert when using herbs, especially in combination with other products or drugs.