For humans, the word “cancer” is usually enough to send anyone running in fear. Fortunately, equine cancer is fairly uncommon, but there are a few we need to consider.

Types of equine cancer
Cancer is the deepest breakdown of the immune system you can have, and consequently can be very difficult to treat. A tumor is produced when the immune system can no longer tell a cell what to do and when to end its life naturally. All cells have a normal lifespan, at the end of which they die off and are replaced by a fresh, young cell. This process is apoptosis. A cancer cell, however, continues to grow and multiply inappropriately. As a tumor gets larger, it will make its own blood supply. In many cases, though, it grows faster than the blood supply can keep up, and you will actually smell tissue breaking down or disintegrating, essentially rotting away.

• The most common skin tumor in horses is a sarcoid, which is usually fairly benign, but can be invasive and quite messy.

• Melanomas are common in grey horses. In some cases, they can be very invasive and large, while in others they remain small until the horse is very old.

• Squamous cell carcinoma can occur around the eye or sheath and may be quite aggressive.

•Cutaneous lymphosarcoma is an uncommon but more serious form of equine cancer, as it involves the lymphatic system (even though you see it on the skin).

• Warts are not actually a cancer, though they have some of the characteristics of a benign tumor, and respond to many of the same treatments.

Traditional treatments
In Western medicine, the goal with a tumor is to cut it out and kill any possible tumor cells with a variety of treatments. When this occurs, the immune system is further weakened, and the disease process continues to get worse. The tumor may be gone, but later in life the horse often gets a similar or different disease (such as allergies, chronic diarrhea, hives, etc.).

A small benign tumor (like a sarcoid) grows slowly, and may never leave a small area. The problem is when you cut out a “quiet” tumor, or treat it in a way that irritates it. If you cut or aggravate the tumor, the body’s immune system may go haywire and make more tumor tissue. This may occur at the original location, or in a new one.

Hint: A tumor means the horse’s immune system is in poor shape.

Sometimes, the tumor is so large or fast growing that it needs to be removed in order to give natural treatments time to work. In other cases, you may choose to have some conventional medical treatment done, and then support the healing process with natural methods. This is commonly done with human cancer treatment, and can be quite successful.

Treating equine cancer holistically
Holistic treatment of equine cancer can range from simple to very complex, depending on the aggressiveness of the tumor and the horse’s own immune system. The goal is to support the body’s immune system to help it kill off tumor cells, using a combination of nutritional supplements, homeopathy or Chinese herbs. Treating equine cancer involves taking a serious look at the horse’s complete history. Due to the complexity of the disease process, it should be done with a holistic veterinarian.

Homeopathy – From the homeopathic perspective, a tumor is an expression produced by the vital force or energy of the body, basically complaining that there is a problem with the body. When a tumor keeps recurring at the same location, it indicates that the vital force is strong yet reminding you that a deep imbalance is still present. If the tumor recurs at other locations, it often means the horse is weaker at a deep level and that it may take longer, or be more difficult, to help or cure him. Having said that, a simple sarcoid may respond well to a few doses of a homeopathic remedy, such as Thuja Occidantalis or Causticum. If you are not familiar with homeopathy, please consult a homeopathic veterinarian.

Herbs – One fairly common treatment for external tumors is bloodroot in a salve format, also called black salve. This herb, in combination with some other compounds, is a powerful anticancer agent. It will eat away at the abnormal tissue and leave the normal tissue alone. This is an effective means of removing simple skin tumors, though it does leave a wound behind that must be treated until it is healed. Remember, however, that something other than a simple sarcoid may be there because of an imbalance in your horse’s energy and immune system. In these cases, it is important to use a complete holistic approach, and not just burn the tumor out with bloodroot.

Nutrition – The foundation of any health program is to feed clean, whole foods, with as little processing as possible. Be sure your environment is not a source of toxins (streams with agricultural run-off as drinking water, sludge used as fertilizer, old orchards used as pasture, etc).

Supplements – May be added to the diet of any horse with a significant type of skin cancer and can include:

Vitamin C – in high doses (10,000 IU), can be an easy, inexpensive immune system regulator that has been used for many types of cancer.

Antioxidant mixtures – sold by a number of companies, they are excellent support nutrients.

Selenium – check to see what the natural level of selenium is in your soil; many parts of the country are deficient. Typically, 2 to 4 mg can be safely added to your horse’s diet. Higher doses require the support of your holistic veterinarian.

Zinc – very important for the immune system and skin. If your horse does not have enough zinc, use the picolinate form and give 200 mg per day.

Vitamin E – especially the succinate and tocotrienol forms. Give up to 500 to 700 IU. This is especially important in areas where fresh green grass is not available, and where pasture is not part of the diet.

Iodine – may be more deficient in horses than we recognize. A kelp-based mineral supplement will get higher levels of iodine into your horse than most other supplements.

Flax, hemp oils or meals – the antioxidant, anti-cancer properties of these oils are well researched. You may use 2 to 4 oz (keep refrigerated). Naturally stabilized ground meal can be used at 4 to 6 oz twice a day, or whole seeds can be fed at the same rate.

Immune supporting products – includes IGG2000 (an immunoglobulin supplement), Artimesinin (an extract from the herb Artimesia), and Fractionated Pectin Powder (an extract from fruit that helps prevent metastasis). Many of these are expensive, so it is best to consult with your vet to help decide what will best benefit your horse.

Mushrooms – such as Shiitake, Maitake, Cordyceps and Corius versicolor have been shown to be very helpful with human and small animal tumors. They get very expensive in horses, so I do not get to use them as often as I would like. Usually 2 to 4 times the human dose works well for this type of supplement.

The most powerful tools in my toolbox for treating most equine cancer are constitutionally prescribed homeopathic remedies, and Chinese herbal formulas based on the Chinese diagnosis of the horse. Since these are individualized, it is beyond the scope of this article to list the related products.

Treating equine cancer can be challenging if you have an aggressive growth, but can also be rewarding if you support the body and its immune system. Remain positive about the outcome of the treatment, and believe in your horse’s natural healing abilities!


Joyce Harman, DVM , MR CVS, graduated in 1984 from Virginia Maryland Regional College of Veterinary Medicine. She is certified in veterinary acupuncture and chiropractic and has completed advanced training in homeopathy and herbal medicine. Her practice in Virginia uses 100% holistic medicine to treat all types of horses . Her publications include The Horse’s Pain-Free Back and Saddle-Fit Book – the most complete source of information about English saddles – and The Western Saddle Book is on its way. www.harmanyequine.com.