In conjunction with Ben Espy, DVM, DACT
A Texas veterinarian is taking a novel approach to sarcoid treatment—removing portions of the tumors, freezing the tissue in liquid nitrogen and implanting it in the same horse’s body. “This is basically a very archaic viral vaccination attempt,” says Benjamin Espy, DVM, DACT, a private practitioner who says the technique has been successful in 12 of 15 documented cases so far. “We want the body to identify the sarcoid as alien and launch its own defense. This vaccine is autologous, which means it was produced from the same source as the animal to whom it was administered.
Horses often develop sarcoids, which are thought to be brought on by the bovine papilloma virus. They may be removed surgically or with lasers, or they can be treated with chemotherapeutic medications like cisplatin. Espy asserts that the sarcoids will reappear if any traces of the growth are still there. “If you take off a huge sarcoid and leave behind even a tiny portion by accident, there might be five, six or 10 billion virus particles in it and the sarcoid will come back, possibly even worse because once they’ve been significantly disturbed, sarcoids can become very ‘angry.’” He claims that a sarcoid vaccination for injection is being developed, although investigations on its effectiveness have generated disagreement.
Espy is a specialist in horse reproductive medicine (theriogenology), but throughout the years, he has seen a number of difficult sarcoid cases related to equine genitalia, which prompted him to explore for more effective techniques to treat the tumors. He cites as an example a stallion that had a large sarcoid on his sheath. You can only make so many cuts in that location.
Espy’s method involves scraping multiple samples the size of pencil erasers off the tumor’s surface, freezing them, and then submerging them in liquid nitrogen to destroy any viruses. Espy inserts the portions along the top of the neck once they have defrosted. “I choose the crest because the skin is thin and the area relatively immobile so it heals quickly and, if there is a scar or white hair accumulation, the mane will cover it.”
So far, says Espy, the technique has been as or more successful than conventional sarcoid treatments he has tried. The tumors typically regress between 90 and 120 days after treatment, but some have taken as long as 180 days to subside. According to Espy, none of the horses had a recurrence. Five years later, the horse he has tracked the longest is still sarcoid-free.
Espy says after presenting a paper on the technique at the 2008 American Association of Equine Practitioners Convention, he was approached by several veterinarians who recalled a similar discussion at the 1975 convention in Nevada. “It’s logical, so I’m sure I’m not the first person who thought of it,” he says, adding that his main goal was sharing information about an effective treatment. I’ll leave it to the dermatologists and pathologists to determine and document the precise reasons why this works, but I’ve observed that it does since I’m a repro man.
Reprinted courtesy of AAEP Media Partner, EQUUS.
Reviewed by author in 2016.