Category Archives: Melanoma

Melanoma in Gray Horses — I can’t ignore it!

This is one subject we all wish would go away.  The good news is that gray horses seem to have mastered the art of surviving melanoma better than any other species that develops them . . . and I’m doing all I can to help my gray horse do just that.

According to Ken Marecella, D.V.M. ,  “A melanoma is a cancer that develops in the melanin cells of the skin. Melanin, the pigment that makes some skin darker than others, is abundant in the skin of gray horses. While horses of other colors can develop melanomas, grays are especially vulnerable.” Marcella tells us, “melanomas in horses are usually only locally invasive and are slow growing. These round black nodules are commonly found near the base of the ears, around the eyes, around the neck and jugular groove (the indentation on the side of the neck where the jugular lies between muscle groups), under the tail and around the vulva or rectum.” (“Gray area, Horses and Horse Information)

While it’s reassuring to know that many veterinarians consider melanomas in gray horses to be slow growing and nonfatal, melanoma researcher John L. Robertson, VMD, MS, PhD, Director of the Center for Comparative Oncology at the Virginia Maryland Regional College of Veterinary Medicine in Blacksburg, VA, warns that melanomas are malignant tumors, and “grow into serious problems in many horses.” (“Don’t Ignore Melanomas,” by Marcia King, The Horse).

Diagnosis: Gross appearance and surgical biopsy are the primary routes to diagnose external melanoma. Even this is complicated, however, because some equine surgeons argue that operating on melanomas “activates” the cells and increases the chances of tumor growth. Internal melanomas can be confirmed through imaging (ultrasound or endoscopy), biopsy or aspiration of masses seen on ultrasound.

Treatment: Emily Graves, VMD, Dipl. ACVIM, founder and principle of Equine Consulting of the Rockies, in Fort Collins, CO, says that “the quantity of tumors, their locations, size, any effects on daily functions/jobs, and biopsy results are used to determine treatment. Some veterinarians prefer to treat more aggressively, encouraging prompt surgical removal of lesions, while other veterinarians favor just monitoring small lesions.” (“Don’t Ignore Melanomas,” by Marcia King, The Horse).

Excision under local anesthesia is sometimes curative for small, superficial melanomas, says Graves, and larger tumors can be removed with laser surgery or surgery under general anesthesia. Non-surgical therapies used to treat melanomas include cimetidine, cisplatin, frankincense oil and melanoma vaccines. (Stay tuned for more details on these alternative treatments.)

Monitoring, Cimetidine, Frankincense and HTA: I have been monitoring a group of small melanomas located under the tail, around the anus and external genitalia of my gray horse for several years. In addition to monitoring the nodules, I have been crushing cimetidine pills and adding 1200 mg of cimetidine to my horse’s feed three times a day — as close to 8 hours apart as possible.  I also treat him with Healing Touch for Animals, using a Magnetic Cleansing over his entire body, adding HTA Ultrasound and Laser on top and under his tail. I augment HTA with Frankincense and Copaiba Essential Oils (from Young Living) whenever I can.

Thus far the melanomas have remained slow growing, but they are growing (one went from dime-size to quarter-size over about five years), and they are increasing in number.

What next? I am going to call Dr. Emily Graves and see what she thinks. I will report back.