Melanomas in Horses: The Problem and Nutrition Alternatives

It's not the sun. It's the STX17 gene.

In humans, UV rays are thought to be a major factor in melanoma growth. In horses, the research points somewhere else: a mutation of a specific gene, STX17, carried by gray and white horses, is where the melanomas originate. That's why the lumps so often form in places that get little or no sun at all: the crest of the mane, under the tail, inside the mouth.

Nobody has found a way to prevent melanomas yet. What you can control is how early you catch them, and whether the feed bucket is working for your horse or against him.

The feed program Rachel built for her own grays.

The feeding approach we suggest for melanoma issues comes from Rachel Kitts, a horse owner who developed it over years of trial and error with her own gray horses, including Trinket, the first horse she helped, and Royal, a flea-bitten gray Arabian she adopted from a rescue.

Her starting point was watching how the usual road plays out. When a melanoma is removed by a vet and tested, it usually comes back benign; yet for some reason they always seem to return, and when they return they seem more aggressive, metastasizing sooner. Vets generally rely on leaving the lumps alone, removing them, or injecting drugs into one to see if it goes away. To Rachel, that is treating a symptom and not the problem: there had to be an initial imbalance in the body first to allow bad cells to proliferate. Her research kept pointing at the same thing, a weakened immune system, and since you are what you eat, strengthening it starts with better nutrition.

The sun plays a part, but not the part most people assume. UV radiation is a real stress for animals with naturally weaker immune systems (white and gray horses, albino dogs and cats), and free radicals help cause cancer by changing the genetic material, the RNA and DNA, of the cell. But the lumps so often form where the sun never reaches that radiation can't be the whole story. What sealed Rachel's stress theory was Trinket herself: her worst masses erupted under her tail not long after she gave birth to a foal, and shrank significantly after two months on the Granules.

Day to day, Rachel keeps it simple: Timothy hay as the main forage with a little Orchard and Oat for variety, the supplements stirred into a wet Timothy-pellet mash ("our horses are in heaven"), free-choice natural salts and minerals, and the Nzymes products below. Alongside the Nzymes line she feeds pure vitamin C (Pure C by VitaFlex), whole flaxseed soaked, never ground or dry, garlic to help keep intestinal parasites down and deter biting flies, and kelp meal (she uses Source) for its packed nutrients. For the salts she buys Redmond, all-natural and right out of the ground; man-made mineral blocks, she's found, don't offer what most horses are lacking.

One more note from her program: alfalfa is a hot feed, and beyond the health risks she's noticed it makes horses take longer to get into a working mindset, "so you are not riding on a 4-legged rocket." The exception is horses in highly physical sports or a mare in foal or lactating; those are the only times she'd add some alfalfa for supplement and variety. Not all cases are the same; some horses improve faster than others, because every body is different. For more on natural horse care, Rachel points readers to Pat Colby's book, which addresses melanomas along with the other illnesses that plague the horse industry.

Trinket, the horse that started it all, has her own page on this shelf: read Trinket's full story →