Texas A&M surgeons use hand-assisted laparoscopy to remove basketball-sized renal tumor in horse

At the Texas A&M University Large Animal Teaching Hospital (LATH), a horse had a 30-lb tumor, larger than a basketball, removed from his left kidney. To remove the mass, an equine soft tissue surgery team at Texas A&M’s LATH had to perform a hand-assisted laparoscopy, a highly complex procedure. According to the lead surgeon, Dustin Major, DVM, a clinical assistant professor in equine soft tissue surgery at the Texas A&M College of Veterinary Medicine & Biomedical Sciences, despite performing laparoscopies often, needing to work inside the abdomen by hand was a rare occurrence.

The mass was discovered by the patient’s local veterinarian after the horse, a 1200-lb warmblood named Sergio, developed 2 episodes of colic within a short period. According to Texas A&M, prior to the colic episodes, Sergio had “been a solid horse for years,” and had not shown any visible signs of illness.

“My vet said, ‘I can tell he is in pain now; you’re going to have to make a decision to try something. Try to do the surgery, or he’s not going to make it,’” Caitlyn Vaughn, Sergio’s owner, said in a Texas A&M report.¹ “She recommended Dr Major at Texas A&M because he’s the most experienced person with this kind of surgery and even wrote the textbook for equestrian kidney surgery.”

The horse behind the case

Outside the hospital setting, Sergio is known as much for his affectionate, social temperament as for his size. Half Friesian and half Morgan, he previously competed in high-level dressage before transitioning into an all-around horse for Vaughn’s family.

“He’s so sweet and lovey-dovey; it’s almost like having a golden retriever,” Vaughn said in the report.¹ “Every time I drive up to the barn, he’s at the back of the paddock, and as soon as he sees me, he whinnies and runs to the gate to greet me.”

Discovering the tumor

When Sergio arrived at Texas A&M’s LATH, the equine soft tissue surgery team performed an ultrasound that clarified the extent of the problem. “We could see normal kidney tissue that then transitioned into this giant tumor that was on the back of his left kidney,” Major said.¹ The mass was large enough to extend across midline and lie against the aorta, raising concern about whether it was adhered to structures that could not be safely separated.

Given the size and location of the mass, the team elected to pursue a hand-assisted laparoscopic approach performed with the horse standing. “We perform laparoscopy often, but it’s unusual to need to work inside the abdomen by hand,” Major said.¹

A complex removal

Once surgery began, the scale of the mass became even more apparent. “Immediately when I got in the abdomen, what we felt before just did not do justice to how big that tumor was,” Major said. Measuring approximately 30 cm in diameter, the mass was larger than a basketball.

The surgical team carefully separated the kidney and associated mass from surrounding tissues and blood supply. The specimen was placed into a sterile retrieval bag within the abdomen and removed in sections because it was too large to extract intact, according to Texas A&M.

Histopathology later identified the mass as a papillary renal carcinoma, a kidney cancer that develops in glandular tissue. According to Major, most horses with this type of tumor have a poor prognosis because metastasis is common by the time of diagnosis.¹ In Sergio’s case, no evidence of spread was identified at the time of surgery, and the papillary subtype is considered less aggressive.

Texas A&M said Sergio’s tumor was an “unusual discovery” because Sergio did not exhibit any kidney-related symptoms and his blood work was normal.

“It’s lucky that he colicked and the tumor was found,” Major said in the report.¹ “Most horses don’t have any reason to suspect a kidney tumor until later, when it has already spread.”

Following surgery and 24 to 48 hours of intensive monitoring, Sergio returned home on a structured rehabilitation plan. Within 8 weeks, Vaughn reported that he had returned to work and was “back to normal.”¹

“I just can’t believe how well the surgery went in general,” Vaughn said.¹ “Dr Major called me after the surgery and [said], ‘This was the most complicated surgery we’ve had in a long time, and it went almost perfectly.’”

Reference

1. Dunn M. A Tall order: Texas A&M vet removes massive kidney tumor from horse. News release. Texas A&M University College of Veterinary Medicine & Biomedical Sciences. February 18, 2026. Accessed March 2, 2026. https://vetmed.tamu.edu/news/press-releases/texas-am-vet-removes-kidney-tumor-from-horse/