Virginia Tech Researchers Trials Focused Ultrasound for Treatment of Equine Sarcoids

This spring, a 9-year-old Hanoverian mare named Pea underwent a groundbreaking procedure at the Virginia-Maryland College of Veterinary Medicine's Teaching Hospital. In this first live trial of its kind, sound waves were used to target and destroy a tumor located on Pea’s belly without the need for surgical intervention, general anesthesia, or a water bath.

Sarcoids are the most common skin tumors in horses, known for being particularly challenging to treat. They arise due to a combination of bovine papillomavirus and a horse's genetic predisposition. If left untreated, sarcoids can become ulcerated, bleed, and attract flies. Traditional therapies often involve surgical removal paired with chemotherapy, but some sarcoids exist in locations that complicate surgical access, while chemotherapy presents risks to handlers.

According to Sophie Bogers, assistant professor of large animal surgery at Virginia Tech, there is no universal solution for sarcoids. In severe cases, owners may find themselves repeatedly managing the condition over months or years, leading some to consider euthanasia as an option.

The histotripsy technology, developed at the University of Michigan, operates by using targeted ultrasound to create bubble clouds that disrupt tumor tissue from within. It has previously shown promise in treating tumors in humans, and has been adapted for use in veterinary medicine by Eli Vlaisavljevich, a biomedical engineer at Virginia Tech. The college has been recognized as one of only 12 Focused Ultrasound Centers of Excellence globally.

Joanne Tuohy, a surgical oncologist at the veterinary college, had already successfully applied histotripsy to treat cancer in dogs, prompting the research team to extend its use to horses. A unique adjustment to the procedure replaced the traditional water bath with a gel-based coupling pad compatible with existing ultrasound technology.

Pea's owner, Kelly Kuykendall, discovered the trial after her veterinarian identified a small growth on Pea's abdomen. After traveling from North Carolina, Pea underwent the treatment, which she tolerated while standing and awake, without any side effects. Bogers described the procedure as a curative excision, with confirmation of tumor destruction through both handheld and robotic devices.

The research team still seeks four more horses to finalize this phase of the study and gain further insights into the effectiveness of histotripsy in preventing sarcoid recurrence. In the future, Bogers aims to create a portable device that can treat sarcoids immediately upon detection, rather than allowing them to develop further before intervention.

Veterinarians interested in referrals or enrolling horses in the trial should note that eligible sarcoids must be of the fibroblastic or nodular type, untreated or recurrent within the last six months. Compensation will cover consultation and surgical expenses, up to $1,500 in hospital costs, with alternatives for those not eligible for live treatment.

Interested participants can contact Large Animal Services at the Virginia-Maryland College of Veterinary Medicine’s Teaching Hospital at 540-231-4621, and are encouraged to email photographs of the sarcoid for assessment. Kuykendall emphasized the importance of addressing these tumors early, stating, “It’s a win-win across the board, for horse owners, for doctors, and for advancement of equine welfare.”

Source: Virginia Tech and the Virginia-Maryland College of Veterinary Medicine.