Horse owners are always on a quest to keep their horses as healthy and happy as possible, often looking outside the traditional veterinary sphere of knowledge for alternative therapies. Keeping the equine immune system healthy to help the horse fight off infection and disease is one particular area where herbals have generated a lot of interest and support.

Shantel Perreal is a certified equine therapist based in Edmonton, AB, with diplomas in massage therapy and rehabilitation, herbology and homeopathy, acupuncture, chiropractics, and kinesio-taping ( She advises that there is no ‘one-size-fits-all’ when it comes to administering herbals as remedies. “I have studied herbals and homeopathics for years with humans and horses, and there is no straight general answer,” she says. “As a whole, no human and no horse are the same. We have to look at everything in the animal’s homeostasis. Environment, food, water, work, stresses, social environment, toxins, etc. Our food has a lot to do with it: my grass is different from my neighbour’s, so all these things are such a huge factor when I am giving any herbs or homeopathic.”

A homeopath or herbalist should also want to see the horse. “There are characteristics that they will look at, such as hair, coat, body condition, gums, saliva, tongue, age, feet.These are just some of the things that will give the practitioner a better idea of how to treat the horse.”

Perreal describes how she proceeds when working with a client’s horse. “As a rule, when helping my client to build up a horse, I suggest taking the horse off of all processed feeds, allowing forage [hay and/or pasture] and going back to basics. Less sometimes is more, even when it comes to the herbals. I am finding a huge amount of new products on the shelves now are done by companies that are just haphazardly mixing these herbs together, while there may only be one herb that the horse needs. When we start mixing too many together, we end up canceling out some of them, and the body will not uptake them and the horse owner sees no results.

“Here is a good example: in springtime, the liver wakes up and it starts to flush itself and the body of toxins from the fall and winter. As soon as you take the horses out to the yard, the first thing that they are trying to eat are the dandelions, even though there are fresh grasses coming up. Dandelion leaf is a great detox for the liver. Milk thistle is one of the components that is put in a liver flush in the stores, as milk thistle is a liver rebuilder. You will find that the horses will go and search these blooms from the thistles in late summer. If you are flushing the liver, you shouldn’t be trying to rebuild it at the same time.

“The liver is a huge organ and one of the most important. It is responsible for so many jobs and we are not helping it by asking it to do too many things at once.”

She adds, “If you are finding immunity low, it could be that the liver is needing help. If I was just to give a horse owner an immune booster and the liver was struggling in the first place, the herbs could hinder the body instead of helping.”

Perreal warns that you should check the credentials of anyone treating your horse. “It is important to look for a herbalist that has their Masters [masters of science degree in herbal therapeutics] or a homeopath that can help you with finding what is needed. Every day I see people that do not truly study these topics and take an online class or a week-long class and feel that they can go out and treat horses.”

She advises to always work with your vet and let him or her know what herbals your horse has been receiving. “Some of these herbs can be very toxic if mixed or administered incorrectly. Always discuss with a vet if they are [being] given any other drugs or medications.”



Benefits: Research has found echinacea to improve immune-system function by increasing the number of lymphocytes in the blood (immune cells which recognize and attack pathogens), encouraging a higher level of hemoglobin and overall improvement of blood quality. This can increase a horse’s defense against microscopic invaders; also promotes healing of wounds when applied topically.

Feeding: It is not recommended that echinacea be given to horses undiluted and is best given to them mixed into their feed. The liquid form is absorbed through the bloodstream more quickly.

Notes: Low daily doses can be given to healthy horses; if you suspect your horse is coming down with a flu or respiratory problem, the dosage can be safely increased. Toxicity and risk of overdose with echinacea is very low.


Benefits: Dandelions contain minerals such as iron, copper and potash, vitamins A, B, C, and D, sodium and calcium, and act as a tonic which stimulates liver and kidney function and bile production. Useful during rehabilitation and recovery from illness, especially for horses that undergo competition stress, or to combat adverse reactions to vaccination.

Feeding: Can be fed fresh as a whole plant (root included) or dried; if the latter, soak in a little water for about five minutes, and then add to your horse’s grain ration.

Notes: The dandelion’s bitterness stimulates the production of stomach acids and digestive enzymes. The leaves’ diuretic effect can relieve fluid retention and help to lower high blood pressure.

SPIRULINA (blue-green algae)

Benefits: Blood building, detoxifying, allergy relief,
and general improvement of the immune system. Good source of protein to aid muscle growth.

Feeding: Has a strong smell but can be mixed with coconut oil, mint, or carrot juice before adding it to your horse’s feed to make it more palatable.

Notes: In its raw state in stagnant water, some blue-green algae produces potent neurotoxins that can cause muscle tremors, respiratory distress, seizures, profuse salivation, diarrhea, and rapid death in horses. Only purchase supplements containing blue-green algae from reputable companies with science supporting their products.

KELP (brown algae)

Benefits: Contains calcium, magnesium, potassium, iodine and iron that improves thyroid and immune functions; has antibacterial and anti-inflammatory benefits. Helps prevent cracked hooves, improves skin texture and coat gloss, minimizes stable vices, speeds up healing time from injuries, increases fertility in broodmares and stallions, promotes regular heat cycles, helps detoxify the body after exposure to mouldy feeds, stimulates appetite and improves digestive capacity.

Feeding: The average horse requires about 2 mg of iodine per day; toxicity occurs at 40mg/day.

Notes: Most horses get sufficient iodine from salt blocks or iodine added to commercial feeds. Iodine toxicity can occur when a horse is fed too much seaweed. Excessive levels of iodine may also cause goiter in foals.


Benefits: An immune system strengthener rich in selenium and sulphur, the latter which has blood-cleansing properties. Garlic has antiseptic, anti-inflammatory, and antibiotic drug-boosting effects; reduces blood pressure, aids with respiratory problems, and even acts as a fly and tick repellent.

Feeding: One-half to two ounces per day, depending on the horse’s size.

Notes: Garlic supplements should be fed with caution, as garlic contains a toxic element called N-propyl disulfide which can affect a horse’s red blood cells and cause anemia. This toxin is destroyed during the manufacturing process when heat dried.


Benefits: Has antioxidant properties to protect the body from cancer, arthritis and cardiovascular disease. Rosehips contain vitamins C, A, K, E, D, thiamine, niacin, and riboflavin. Research has confirmed that a protein present in rosehips could help prevent the onset of osteoarthritis through boosting the immune system, shielding joint tissue from harmful materials. Helps horses fight off infections, improves hoof growth, and boosts immune health.

Feeding: Create a tea from the rosehips and pour over the horse’s grain, or chop up and add to the feed.

Notes: May give your horse diarrhea if too much overall vitamin C is fed. The high sugar content of rosehips is a concern if your horse has laminitis or other metabolic or insulin-related problems.


Benefits: Promotes healthy joints, balances the horse’s pH, boosts immune system health, helps dissolve calcium deposits (enteroliths) in the digestive system, improves urinary tract health and mineral absorption, flushes toxins, regulates insulin response, relieves arthritis symptoms. Encourages healing when diluted and sprayed on skin fungus, burns, and infections.

Feeding: ¼ cup daily on feed, diluted with equal amount of water.

Notes: Ingested apple cider vinegar can be used for insect control, as it results in the excretion of high levels of thiamine (vitamin B1) through the skin. It also makes a great mane-and-tail conditioner when a cup is added to the rinse water!

Other herbs with some purported immune-boosting, blood-cleansing or detoxification properties include Guduchi Vine, Winter Cherry, Amla Berry, Cleaver, Hawthorne Berry, Nettle, Red Clover, and Pau De Arco Bark. Speak to a certified equine herbologist or homeopathic expert about which herbal products might be right for your horse

The immune system is the body’s natural defense system, a network of cells, tissues, and organs that work together to defend against invading disease organisms or allergens. The stress of competition or travel, fatigue, aging or illness may deplete the immune system; immune boosters and detoxifiers are purported to assist in re-strengthening it.

Drug/Herbals to Avoid

While some drugs and herbs can safely be used simultaneously – antibiotics and echinacea, for example – some should not be, including:

Chamomile: has the potential for increased clotting time when used with non-steroidal anti-inflammatory drugs, or drugs that influence clotting. Also potential interaction with sedatives/tranquilizers, narcotics and anesthetics

Devil’s Claw: similar to chamomile re: clotting. May irritate stomach ulcers, so not to be used in horses being treated for such.

Echinacea: Corticosteroids can counteract the effect. Echinacea may increase respiratory or skin allergies.

Garlic: May increase clotting time when used with NSAIDs or drugs that influence clotting.

Ginseng: May increase clotting time when used with NSAIDs or drugs that influence clotting; may also interfere with pain-relieving effects of narcotics.

Licorice: Can increase the side-effects of corticosteroids and if used with diuretics can lead to increased loss of potassium (electrolyte) in the urine.

Chastetree Berry/Monk’s Pepper: Low dose may worsen some Cushing’s symptoms; may interact with domperidone, a drug used to treat tall fescue toxicosis, or ovulation-control drugs (estrogens or progestins) such as Regumate.